The Camp System

Why this Topic exists

A camp was not a single kind of place.

The standard secondary-school treatment of the Nazi camp system typically uses the term "concentration camp" to refer to the entire architecture, with "Auschwitz" as the most familiar example. This usage is conventional but historically imprecise. The Nazi regime operated multiple distinct camp types with different purposes, different prisoner populations, different death rates, and different relationships to the broader genocidal apparatus. The distinction between a concentration camp and a killing center is the most important, concentration camps were sites of imprisonment, brutalization, and exploitation in which death was common; killing centers were dedicated facilities for the systematic murder of populations on arrival. Both existed within the same Nazi system, but they performed different functions. The distinctions matter because each type of camp served a different purpose within the broader Nazi system and generated different kinds of historical records. Understanding those differences helps students interpret documents, testimony, photographs, and postwar evidence more accurately.

The principal scholarly reference for the camp system as an architecture is the United States Holocaust Memorial Museum's Encyclopedia of Camps and Ghettos, 1933–1945, a multi-volume documentary project that has so far documented more than 44,000 individual sites (concentration camps, forced-labor camps, transit camps, ghettos, prisoner-of-war camps with substantial Jewish populations, and other categories) across occupied Europe.

The categories of camps

Five types, briefly distinguished.

The scholarly literature distinguishes five principal categories of Nazi camps. The categories are analytical rather than absolute; some individual sites combined more than one function over time. The categorical distinctions nonetheless capture the structure of the system.

• Concentration camps: sites of imprisonment, forced labor, and systematic brutalization. The original Nazi camp system, beginning at Dachau in March 1933. Prisoners included political opponents of the Nazi regime, persons identified as racially or socially "undesirable," and from the late 1930s increasingly Jewish prisoners. Death rates were high; the camps were not, in the classical sense, designed for the immediate murder of arriving populations.
• Killing centers (extermination camps): dedicated facilities for the systematic murder of populations on arrival, primarily by gas. Six killing centers operated, all in occupied Poland: Chełmno, Bełżec, Sobibór, Treblinka, Auschwitz-Birkenau, and Majdanek. The killing centers are the facilities at which the largest concentration of Jewish murders took place.
• Forced-labor camps: sites where Jewish and other prisoner populations were exploited as forced labor for German industrial, agricultural, military, and infrastructure purposes. The largest single category of camps in the USHMM Encyclopedia of Camps and Ghettos, including thousands of sites of varying size across occupied Europe.
• Transit camps: sites used for the temporary holding of populations awaiting deportation, typically to the killing centers. The major transit camps included Westerbork (Netherlands), Drancy (France), Theresienstadt (in occupied Czechoslovakia, also functioning as a ghetto and a propaganda site), and Mechelen (Belgium).
• Prisoner-of-war camps with substantial Jewish populations. A distinct category in the historical record because the Nazi regime treated Jewish prisoners of war, particularly Soviet Jewish prisoners, under separate, more deadly conditions than non-Jewish prisoners of war. The treatment of Soviet Jewish POWs is part of the genocidal record, distinct from the standard POW regime under the Geneva Convention.

Concentration camps

The original Nazi camp system, 1933–1945.

The Nazi concentration-camp system began on March 22, 1933, less than two months after Adolf Hitler's appointment as Chancellor of Germany, with the opening of Dachau near Munich. Dachau was established by the SS under the authority of Heinrich Himmler, who would shortly become the principal architect of the broader SS camp system. The original purpose of Dachau was the imprisonment of political opponents of the Nazi regime, communists, social democrats, trade unionists, and other categories of political prisoner. The design of Dachau provided the model for the subsequent expansion of the system.

Across the 1933–1939 period, the SS established the principal pre-war concentration camps: Sachsenhausen (1936, near Berlin), Buchenwald (1937, near Weimar), Flossenbürg (1938), Mauthausen (August 1938, in annexed Austria), and Ravensbrück (1939, for women). Prisoner populations across this period were primarily political prisoners, persons identified as criminal recidivists under the Nazi regime's expanded category, and persons targeted on racial grounds (Roma and Sinti, persons identified by Nazi categorization as "asocial," gay men under the Paragraph 175 framework, Jehovah's Witnesses, and others). Jewish prisoners were a smaller component of the pre-war camp population, with the major exception of the Kristallnacht period (November 1938) when approximately 30,000 Jewish men were arrested and sent primarily to Dachau, Buchenwald, and Sachsenhausen.

The wartime expansion of the concentration-camp system, after September 1939, brought a fundamental change in scale and function. New camps were established across occupied Europe, including Auschwitz I (May 1940), Stutthof (near Danzig, August 1939), Gross-Rosen (1940), Natzweiler-Struthof (1941, in occupied France), and many others. The prisoner population expanded to include Polish political prisoners and intellectuals, Soviet prisoners of war (subject to the deadly conditions noted above), Jewish prisoners from occupied territories, and persons targeted as racial and political enemies of the Nazi regime across the conquered countries. By 1944, the concentration-camp system included more than twenty principal camps and hundreds of subcamps.

Death rates in the concentration camps varied across camps, periods, and prisoner categories. Mauthausen and its subcamps were distinguished by exceptionally severe conditions; the same was true of certain subcamps of Buchenwald (Dora-Mittelbau, where the V-2 rocket was produced under conditions designed to kill the prisoner population through exhaustion) and of Gross-Rosen. The death rates in the concentration camps were, in a sense, byproducts of the conditions of imprisonment rather than the operational purpose of the camps. This is the distinction that separates them from the killing centers.

The six killing centers

The dedicated facilities of the Final Solution.

The killing centers were the principal sites of systematic mass murder during the Holocaust and the places where the greatest number of Jews were murdered. All six were in occupied Poland. They operated under different organizational frameworks, three under Operation Reinhard (Bełżec, Sobibór, Treblinka), one under independent SS operation (Chełmno), and two as composite facilities combining killing-center and concentration-camp functions (Auschwitz-Birkenau and Majdanek). The combined number of people murdered at the six killing centers is estimated at approximately three million, the great majority Jewish.

The history of each killing center is documented in detail in the scholarly literature, most authoritatively in Yitzhak Arad's Belzec, Sobibor, Treblinka: The Operation Reinhard Death Camps (Indiana University Press, 1987, revised 1999), in the various works of Christopher Browning, in the USHMM Encyclopedia of Camps and Ghettos Volume I, and in the documentation of each surviving memorial site.

Chełmno · December 1941 – March 1943, briefly reactivated 1944

The first dedicated killing center.

The killing center at Chełmno (German: Kulmhof) opened on December 8, 1941, at a former manor estate about 50 kilometers northwest of Łódź in occupied Poland. It was the first dedicated facility of the Nazi regime designed for the systematic murder of populations on arrival.

The killing method at Chełmno was the gas van, a sealed truck into which the exhaust was channeled. Victims were brought to the manor house, told they would be processed for resettlement, and were then loaded into the gas vans in groups of about 50 to 70 people. The vans drove to a nearby forest, the killing took place during the drive, and the bodies were buried (and later, beginning in 1942, exhumed and cremated to destroy evidence).

Chełmno operated in two phases. The first phase, December 1941 to March 1943, was the principal operational period. Approximately 152,000 to 180,000 people were murdered, the great majority Jewish, primarily from the Łódź Ghetto and the surrounding region of the Wartheland. The second phase, June to July 1944, operated briefly during the final liquidation of the Łódź Ghetto; an additional approximately 7,000 to 8,000 people were murdered before the camp was abandoned in advance of the Soviet advance.

Two prisoners survived Chełmno, Mordechai Podchlebnik and Szymon Srebrnik, and provided survivor testimony that constitutes among the earliest direct survivor accounts of the killing-center system. Srebrnik's testimony is preserved on film in Claude Lanzmann's Shoah (1985); both survivors testified at postwar trials. The site at Chełmno is preserved as the Chełmno Museum.

Bełżec · March 1942 – December 1942

The first Operation Reinhard killing center.

The killing center at Bełżec opened on March 17, 1942, in the Lublin district of the General Government (occupied Poland). It was the first of the three killing centers established under Operation Reinhard, the code name for the operation to murder the approximately two million Jews of the General Government, named after Reinhard Heydrich (the SS officer who had convened the Wannsee Conference and who was assassinated by Czech resistance fighters in May 1942).

The killing method at Bełżec was carbon-monoxide gas chambers, with carbon monoxide produced by diesel engines and pumped into sealed chambers. Victims were brought by train from the Jewish communities of the General Government (primarily from Lwów (Lviv), Lublin, Kraków, and the surrounding regions) and were murdered on arrival, typically within hours of the train's arrival at the camp.

Bełżec operated for approximately nine months. Approximately 434,500 people are documented as having been murdered there in that period, the overwhelming majority Jewish. The figure is among the most precisely documented in the killing-center system because of the extraordinary survival of a single contemporary document, a January 1943 radiogram from SS officer Hermann Höfle to Berlin reporting the cumulative Operation Reinhard murder figures by camp through the end of 1942. The Höfle Telegram, intercepted and decrypted by British intelligence and released to scholars in 2000, established the precise documentary record for Bełżec, Sobibór, Treblinka, and Majdanek through the end of 1942.

Two prisoners survived Bełżec, Chaim Hirszman, who was murdered after the war during the Kielce-region pogroms, and Rudolf Reder, who testified at postwar trials. The site at Bełżec is preserved as the Bełżec Museum.

Sobibór · May 1942 – October 1943

The killing center that ended in revolt.

The killing center at Sobibór opened in May 1942 in the Lublin district. The killing method was carbon-monoxide gas chambers, parallel to Bełżec. Sobibór received transports primarily from the General Government, from the Netherlands (the Westerbork transit camp), from France (via Drancy), and from other Western European countries. Approximately 167,000 people are documented as having been murdered at Sobibór, the overwhelming majority Jewish.

Sobibór is distinguished by the revolt of October 14, 1943, in which approximately 300 prisoners of the special detail forced to operate the killing process organized an armed uprising. The uprising was led by Alexander "Sasha" Pechersky, a Soviet Jewish prisoner of war who had arrived at Sobibór in September 1943, working with Polish Jewish prisoner Leon Feldhendler. The uprising killed approximately 11 SS guards and produced the escape of some 300 prisoners; an estimated 50 of those survived the war.

The Sobibór revolt was consequential. The Nazi regime closed the camp in the immediate aftermath, dismantled the facilities, and attempted to obscure the site by planting trees over the buried evidence. The site at Sobibór is preserved as the Sobibór Museum, with extensive archaeological recovery work conducted since the 2000s.

Treblinka · July 1942 – November 1943

The killing center that murdered the Warsaw Ghetto.

The killing center at Treblinka (Treblinka II in the precise terminology, distinguishing the killing center from the adjacent forced-labor camp Treblinka I) opened on July 23, 1942, in the Generalgouvernement, about 80 kilometers northeast of Warsaw. The killing method was carbon-monoxide gas chambers.

Treblinka was the principal killing center for the Jewish community of Warsaw. The deportations from the Warsaw Ghetto to Treblinka, which began on July 22, 1942, and continued through September 1942 (the "Great Deportation"), murdered approximately 265,000 of the roughly 380,000 inhabitants of the ghetto at the time of the deportations. The systematic murder of the Warsaw Jewish community at Treblinka is documented in survivor testimony, in postwar trial records, and in the Ringelblum Archive (the clandestine documentary archive maintained inside the Warsaw Ghetto by historian Emanuel Ringelblum and his associates, preserved in milk cans and metal boxes buried beneath the ghetto and recovered after the war).

The total number of people murdered at Treblinka is estimated at approximately 925,000, the second-largest killing-center death toll after Auschwitz-Birkenau. Almost all of those murdered at Treblinka were Jewish; smaller numbers of Roma were also murdered there. A prisoner uprising on August 2, 1943, parallel to the later Sobibór revolt, killed several SS personnel and produced the escape of some 200 prisoners, of whom approximately 70 survived the war. The Treblinka site was dismantled by the Nazi authorities after the uprising; the site is preserved as the Treblinka Museum with a substantial postwar memorial designed by Adam Haupt and Franciszek Duszeńko.

Majdanek · October 1941 – July 1944

The composite camp on the edge of Lublin.

Majdanek (formally KL Lublin) was a distinct case: a composite facility that operated simultaneously as a concentration camp, a forced-labor camp, a Soviet prisoner-of-war camp (in its earliest phase), and a killing center. The camp was established in October 1941 on the southeastern outskirts of Lublin in occupied Poland. The gas chambers were installed in late 1942 and operated through November 1943.

Majdanek is distinct in two further respects. First, the camp was located within the boundaries of a major Polish city, Lublin, rather than in a remote location. The proximity of the camp to the civilian population produced a more substantial body of contemporary documentation than the more isolated Operation Reinhard sites. Second, Majdanek was the first major killing center to be liberated by Allied forces. Soviet forces overran the camp on July 23, 1944, capturing the gas chambers and crematoria substantially intact and producing the first published photographic and documentary evidence of the killing-center system to reach the international press.

The total number of people murdered at Majdanek is estimated by the principal scholarly literature at approximately 80,000, with an estimated 60,000 of those being Jewish. The site is preserved as the Majdanek State Museum, with the original gas chambers, crematorium, and substantial parts of the camp infrastructure intact.

Auschwitz-Birkenau · May 1940 – January 1945

The largest of the killing centers.

The Auschwitz complex was the largest and the most complex of the Nazi camp facilities. It consisted of three main camps and approximately 45 subcamps spread across the Silesian region of annexed Polish territory. The three main camps:

• Auschwitz I (Stammlager): the original camp, established on May 20, 1940, in the former Polish military barracks at Oświęcim. Functioned as the administrative center of the complex, as a concentration camp for political prisoners (initially primarily Polish), and after the start of the killing operations also as a site of mass murder. Holds the iconic Arbeit Macht Frei gate.
• Auschwitz II–Birkenau: the main killing center, established in October 1941 about three kilometers from Auschwitz I, in the village of Brzezinka. Birkenau was the principal site of the gas chambers and crematoria of Auschwitz, with four major gas-chamber-crematorium complexes (Crematoria II, III, IV, and V) and the railhead at which incoming transports were processed and selections made.
• Auschwitz III–Monowitz: established in October 1942 as the Buna labor camp for the IG Farben synthetic-rubber plant, this became the principal forced-labor component of the complex. Primo Levi, the Italian Jewish chemist and writer whose If This Is a Man is among the most influential survivor memoirs, was imprisoned at Monowitz.

The total number of people murdered at Auschwitz is documented by the scholarly literature, most authoritatively by Franciszek Piper of the Auschwitz-Birkenau State Museum, whose Auschwitz: How Many Perished, Jews, Poles, Gypsies (1994) established the precise figure, at approximately 1.1 million people. Of those, approximately 1.0 million were Jewish, approximately 70,000–75,000 were Polish political prisoners, approximately 21,000 were Roma and Sinti, approximately 14,000 were Soviet prisoners of war, and approximately 10,000–15,000 were prisoners of other nationalities and categories.

The killing operations at Auschwitz-Birkenau reached their peak in spring and summer 1944 during the deportation of the Hungarian Jewish community. Between May 15 and July 9, 1944, approximately 437,000 Hungarian Jews were deported to Auschwitz, with an estimated 320,000 murdered on arrival in under six weeks. The Hungarian deportations were the largest and most concentrated phase of mass murder in the Holocaust.

The Auschwitz complex was liberated by Soviet forces on January 27, 1945, the date the United Nations later designated as International Holocaust Remembrance Day. At the moment of liberation, approximately 7,000 prisoners remained in the camp; the remaining inmates had been forcibly evacuated westward in death marches in mid-January 1945. The site is preserved as the Auschwitz-Birkenau State Memorial and Museum, the largest Holocaust memorial site in the world. The complex was inscribed on the UNESCO World Heritage List in 1979.

Forced-labor camps

The largest single category of camps.

Forced-labor camps were the sites at which Jewish and other prisoner populations were exploited as labor for German industrial, agricultural, military, and infrastructure purposes. The category includes:

• SS-administered forced-labor camps: labor camps directly under the SS Economic and Administrative Main Office (SS-WVHA), often as subcamps of the major concentration camps. The SS leased prisoner labor to German industrial firms for substantial fees.
• Wehrmacht-administered camps: labor camps under German military administration, particularly in the early war years.
• Civil-administration camps: labor camps under various German civilian administrative bodies, including the Organisation Todt (responsible for major military and infrastructure construction).
• Industry-administered camps: labor camps operated by specific German industrial firms (IG Farben, Krupp, Siemens, Daimler-Benz, BMW, and many others) using leased prisoner labor under the broader SS framework.

The death rate in the forced-labor camps varied substantially. Conditions in many camps, particularly those engaged in heavy construction or in production with dangerous materials, produced high mortality. The Dora-Mittelbau camp at Nordhausen, where prisoners produced the V-2 rocket, the Dora-Ellrich subcamp, and many of the Mauthausen subcamps had particularly high death rates. Other forced-labor camps maintained the prisoner population at lower mortality on the logic that labor productivity required it.

The forced-labor system was integrated with the killing operations. At Auschwitz-Birkenau and at Majdanek, prisoners deemed fit for labor at the initial selection were typically sent to forced-labor work within the complex or to subcamps; prisoners deemed unfit for labor were murdered on arrival. The labor system and the killing system were distinct, but closely interconnected. Prisoners selected for work could later die from starvation, disease, execution, or subsequent transfer to killing centers.

The USHMM Encyclopedia of Camps and Ghettos Volumes I and II document approximately 30,000 forced-labor camp sites, including subcamps of all sizes. The record is extensive; individual labor-camp histories are documented at varying levels of detail in the scholarly literature.

Transit camps

The way-stations to the killing centers.

The Nazi regime operated a network of transit camps in occupied Western and Central Europe, sites at which deportees were held temporarily before transport, typically eastward to the killing centers. The major transit camps:

• Westerbork (Netherlands): the principal transit camp for the deportation of the Dutch Jewish community. Westerbork had been established by the Dutch government in 1939 as a refugee camp for Jewish refugees from Germany; it was repurposed under the German occupation in 1942 as a transit camp. Approximately 107,000 of the 140,000 Dutch Jewish community were deported through Westerbork, primarily to Auschwitz and Sobibór. Anne Frank and her family were deported from Westerbork to Auschwitz on September 3, 1944.
• Drancy (France): the principal French transit camp, in a suburb of Paris. Approximately 65,000 French Jews and Jews resident in France were deported through Drancy, the great majority to Auschwitz.
• Mechelen (Belgium): the principal Belgian transit camp, in the Mechelen Kazerne (military barracks). Approximately 25,000 Belgian Jews and Jews resident in Belgium were deported through Mechelen, primarily to Auschwitz.
• Theresienstadt (Terezín, Czechoslovakia): the distinctive case. Theresienstadt was officially designated as a transit camp and "model ghetto," used by the Nazi regime for elderly German and Austrian Jews, certain categories of decorated First World War veterans, and prominent Jewish individuals. It also served as a Nazi propaganda site, the regime used Theresienstadt to demonstrate to international observers (most prominently the International Red Cross in June 1944) the supposed humane treatment of Jewish populations. Approximately 33,000 prisoners died at Theresienstadt itself; an estimated 88,000 were deported from Theresienstadt eastward to the killing centers, primarily Auschwitz. Theresienstadt produced a substantial cultural and intellectual life among its inmates (concerts, lectures, art, and the surviving children's drawings of Friedl Dicker-Brandeis's art classes) that has become the basis of substantial postwar memorial and educational work.
• Risiera di San Sabba (Italy): the only Nazi camp with a crematorium on Italian soil, in Trieste. Functioned as a transit camp and as a site of murder, particularly for Italian Jews and partisans.

The transit camps are important to the historical record because they were the points at which the deportations from Western Europe were administratively organized. The surviving documentation from the transit camps (registration lists, transport records, correspondence) provides substantial primary-source material for the documentation of the Western European Jewish communities that did not survive.

The camps and the towns around them

How close the camps were to ordinary life.

The camps were not hidden away in secret wilderness. Many stood beside the towns and cities where people lived. Dachau sat at the edge of a Bavarian market town of the same name. Majdanek was built on the outskirts of Lublin, a city of more than 100,000, its watchtowers visible from the streets. Buchenwald overlooked Weimar, the city of Goethe and German high culture. Residents saw the columns of prisoners marched out to work, watched the transports come and go, and lived with the smoke and the smell from the crematoria.

The camps were woven into the economy around them. The SS leased prisoner labor to German firms (among them IG Farben, Krupp, and Siemens, and hundreds of smaller companies) for a daily fee per prisoner. Local builders, suppliers, railway crews, and civil servants did business with the camps, which were run openly by salaried officials and recorded in ordinary paperwork.

The killing centers were the exception. The dedicated sites were placed in more remote locations and disguised as transit stations, to conceal the murder itself even where the deportations that fed them were public. How much surrounding populations knew, how that knowledge varied from place to place, and how individuals responded remain important questions in Holocaust scholarship.

The youngest victims

Children in the camp system.

Children occupied a specific place in how the camps worked. At the killing centers, the selection on the arrival ramp turned on a single question, decided by the SS physicians who ran it: could this person be put to work? Children (like the elderly, the sick, and pregnant women) almost always could not, and so they were sent straight to the gas chambers, unregistered, within hours of stepping off the train. Most of the roughly 1.5 million Jewish children murdered in the Holocaust were killed this way, or earlier, in the mass shootings and the ghettos.

A small number of children were kept alive for specific reasons. At Auschwitz, the SS doctor Josef Mengele selected twins and certain other children for medical experiments; older teenagers were sometimes registered for forced labor. The transit camp and “model ghetto” of Theresienstadt was an exception of a different kind: the imprisoned adults, among them the artist Friedl Dicker-Brandeis, organized secret lessons, concerts, and art classes for the children held there. About 15,000 children passed through Theresienstadt; fewer than 200 survived. Roughly 4,500 of their drawings, hidden and recovered after the war, are held today by the Jewish Museum in Prague.

The Nazis also built camps specifically to hold children. The largest was the children’s camp at Litzmannstadt, the German name for Łódź, opened in December 1942 in a fenced-off section carved out of the Łódź Ghetto. It held Polish children, most of them not Jewish: orphans, the children of arrested resistance members, and others taken off the streets, some as young as six. They were put to forced labor (weaving baskets, making straw shoes, sewing and repairing uniforms) on starvation rations, and an unknown number died of hunger, disease, and beatings before the camp was liberated in January 1945. Inside Germany, the regime ran two youth concentration camps of its own, Moringen for boys and Uckermark for girls, for adolescents it labeled “asocial” or “criminal,” where the prisoners were examined, sorted by the regime’s racial criteria, and worked.

Of the more than 230,000 children and teenagers deported to Auschwitz, only a few hundred were alive when Soviet forces reached the camp in January 1945.

The Nazi ghetto distinction

A reminder of the categorical separation.

The Nazi-era ghettos (Warsaw, Łódź, Vilna, Kraków, Lublin, Białystok, and approximately 1,000 smaller ghettos across occupied Eastern Europe) are a related but distinct category. The Nazi-era ghettos were sealed urban districts in occupied territory, primarily in Poland and the Baltic states, into which Jewish populations were concentrated under conditions of extreme overcrowding, starvation, and forced labor in advance of deportation to the killing centers.

The Nazi-era ghettos are categorically and historically distinct from the early-modern European ghetto system documented in Topic · The Ghetto System. The early-modern ghettos were enduring residential arrangements operating across centuries; the Nazi-era ghettos were transitional concentration sites maintained for two to four years before the deportation of their populations. The terminology is the same; the reality is not. The platform preserves the distinction in every page that touches the subject.

The full treatment of the Nazi-era ghettos is treated in the Nazi Ghettos Topic and in Unit 4's chronology. The Warsaw Ghetto Uprising of April–May 1943 is the most documented case; the Łódź Ghetto under Mordechai Chaim Rumkowski is the most analytically debated case; the Vilna Ghetto and its cultural and resistance institutions, the Białystok Ghetto Uprising of August 1943, and the Kraków Ghetto under Tadeusz Pankiewicz's pharmacy at the edge of the ghetto are each the subject of substantial scholarly literature.

The final months

Evacuations, death marches, and liberation.

As the Soviet army advanced from the east through 1944, the SS began emptying the camps in its path rather than let the prisoners be freed. Majdanek was overrun so quickly in July 1944 that much of it was captured intact, the first major camp the Allies reached, and early physical proof of what the killing centers had been. To keep that from happening again, the SS drove the prisoners of the remaining camps westward, on foot and in open rail cars, through the winter of 1944–45.

These forced evacuations became known as the death marches. Prisoners already starved and worked to exhaustion were moved for days or weeks in the cold with little or no food; those who fell behind or could not keep pace were shot at the roadside. The largest began in mid-January 1945, when about 56,000 prisoners were marched out of the Auschwitz complex days before Soviet troops arrived. Historians estimate that a quarter of a million prisoners or more died on the marches and in the overcrowded camps they were driven into, among them Bergen-Belsen, which had no gas chambers and yet saw tens of thousands die of starvation and typhus in the final weeks.

Liberation came unevenly, camp by camp, as the front lines reached them. Soviet forces entered Auschwitz on January 27, 1945, finding about 7,000 prisoners too weak to be moved. That spring, American and British troops reached the camps inside Germany (Buchenwald, Dachau, Bergen-Belsen, Mauthausen) and what they found was recorded in film and photographs that carried the evidence to the world. For many survivors, liberation was not an ending but the start of years in displaced-persons camps, searching for family who in most cases had not survived. January 27 is now observed as International Holocaust Remembrance Day.

The documentary record

How we know what we know.

The Nazi camp system is among the most extensively documented subjects in modern history. The documentary record is preserved across multiple channels:

• The Nazi regime's own administrative records: preserved in substantial measure despite extensive Nazi efforts to destroy evidence in the final months of the war. The Höfle Telegram (a January 1943 Operation Reinhard radiogram intercepted and decrypted by British intelligence and released to scholars in 2000), the Wannsee Conference minutes drafted by Adolf Eichmann, the surviving documentary records of the SS Economic and Administrative Main Office, the records of the killing centers themselves where they survived, and the corporate records of the German firms that participated in the system are the principal categories.
• The postwar trial records: the Nuremberg Trials (1945–1949), the Frankfurt Auschwitz Trial (1963–1965), the Düsseldorf Treblinka Trial (1964–1965), the Eichmann Trial in Jerusalem (1961), and the long series of subsequent trials in Germany, Israel, Poland, and other countries produced extensive documentary records, witness testimony under oath, and the cumulative documentation that has anchored the scholarly literature.
• The survivor testimony archive: the testimony archives at Yad Vashem, the USHMM, the USC Shoah Foundation, the Fortunoff Video Archive at Yale, and the collections of the major Jewish historical archives.
• The research of the major memorial museums: particularly the Auschwitz-Birkenau State Museum (which has produced a continuous body of scholarly research on the camp since its establishment in 1947), Yad Vashem's research institutes, and the USHMM's Center for Advanced Holocaust Studies.
• The USHMM Encyclopedia of Camps and Ghettos: the systematic documentation of more than 44,000 individual sites across the Nazi system, conducted by the USHMM's Mandel Center and published by Indiana University Press in seven volumes between 2009 and 2024.

The camps today

The preserved sites and what to know before visiting.

The principal camp sites are preserved as memorial museums. They are accessible to scholars, teachers, students, and the general public; the pedagogy that the major sites have developed across decades is substantial.

Key takeaways

The record in brief.

• The Nazi camp system consisted of several distinct types of camps, each created for different purposes.
• Concentration camps imprisoned, exploited, and brutalized prisoners, and death was common; killing centers were built for the murder of arriving populations, primarily by gas.
• All six killing centers (Chełmno, Bełżec, Sobibór, Treblinka, Majdanek, and Auschwitz-Birkenau) operated in occupied Poland.
• Auschwitz-Birkenau and Majdanek combined killing-center, concentration-camp, and forced-labor functions in one complex.
• Forced-labor camps were the largest category by number of sites; the SS leased prisoner labor to German firms for a daily fee.
• Transit camps such as Westerbork, Drancy, Mechelen, and Theresienstadt held deportees from Western and Central Europe before transport eastward.
• The system is documented across Nazi records, postwar trials, survivor testimony, and the USHMM Encyclopedia of Camps and Ghettos, which has catalogued more than 44,000 sites.

Discussion questions

For classroom use.

1. The Topic distinguishes a concentration camp from a killing center by purpose. How would you explain that distinction to someone who has only ever heard the phrase “concentration camp”?
2. Many camps stood near towns and cities, while the killing centers were placed in more remote locations. What does that difference suggest about what the regime tried to make public and what it tried to conceal?
3. The Höfle Telegram and the Ringelblum Archive reached historians by very different routes. What does each kind of source allow us to know, and what are the limits of each?
4. The Sobibór and Treblinka revolts are documented in survivor testimony. What questions would you want to ask before drawing conclusions from a single survivor’s account?
5. Using the Auschwitz selection process, how were the forced-labor system and the killing system linked?
6. Why might historians treat the number of victims at some camps as well-documented while describing others as estimates?

For the classroom

Where this Topic fits the standards.

• World History, NY Global History 10.5 (World War II and the Holocaust). Examines the structure and function of concentration camps, labor camps, transit camps, and killing centers within the Holocaust.
• NYS Holocaust Education Mandate, Education Law §801. Supports Holocaust instruction by distinguishing the different types of camps and correcting common misconceptions.
• Common Core RH.11–12.6 & RH.11–12.9. Students analyze camp records, maps, photographs, survivor testimony, and historical scholarship.
• C3 Framework, D2.His.1, D2.His.14. Students investigate historical categorization, chronology, and evidence.
• Classroom Applications. Differentiate camp types, analyze historical terminology, interpret documentary evidence, and evaluate historical misconceptions.
• International Classroom Relevance. Supports Holocaust education, genocide studies, and museum education.

Resources, lessons, and video

Where to teach this well.

The major Holocaust institutions have built decades of classroom material on the camps. This Topic supplies the framework; the lessons, testimony, and visual material below are where to teach from, the platform points to that work rather than duplicating it.

Teacher materials & lesson plans

• USHMM · Teaching Materials, guidelines for teaching the Holocaust, ready lessons, and the searchable Holocaust Encyclopedia entries on every camp named here.
• Yad Vashem · International School for Holocaust Studies, lesson plans and units organized by grade band.
• Echoes & Reflections, a full classroom curriculum (its unit on the “Final Solution” covers the camps and killing centers) with survivor testimony built in.
• Facing History & Ourselves, lessons that set the camps within the choices and steps that led to them.

Testimony & video

• USC Shoah Foundation · IWitness, survivor video testimony with built-in, standards-aligned activities.
• The National WWII Museum · “The Liberation of Auschwitz”, a sourced classroom article on what the liberators found and how the world learned of it.
• Auschwitz-Birkenau Memorial · online panorama, a guided virtual walk through the preserved site for classrooms that cannot travel.
• USHMM · classroom film, The Path to Nazi Genocide, the museum’s free 38-minute overview film for secondary classrooms, with a viewing guide. Grades 9–12.

For New York–region teachers. The Holocaust Memorial & Tolerance Center of Nassau County (Glen Cove, Long Island) runs in-school programs and a Speakers Bureau, and offers a free virtual guide to its galleries, including one on life in the camps.