Established in 1933, 10 miles northwest of Munich on the outskirts of a town called Dachau, this concentration camp would initially house 5,000 political prisoners. The number of those opposed to the Nazi regime would increase from the original Communists it held. Soon it would include Roma (Gypsies), religious dissenters (Catholic priests and nuns, Protestant ministers, Jehovah’s Witnesses etc.) repeat criminals and homosexuals. In 1938, Jews began becoming a large number of those sent to this camp.
Dachau prisoners were used as forced laborers for German armaments production and was used as a training facility for SS concentration camp guards. Prisoners were also used in hideous medical experiments resulting in many dying or being crippled for life. While many thousands died at Dachau, many were sent to the extermination center near Linz, Austria until a gas chamber and crematorium were added in 1942. Satellite camps supplemented the main camp and were set up near armaments factories. Collectively all these camps were administered by Dachau and part of it.
The situation by April 1945 was dire for Germany with Allied forces closing in. Many prisoners were sent from camps nearer the front to Dachau resulting in epidemics and overcrowding. Over 7,000 mostly Jewish prisoners were forced to March from Dachau to Tegernsee in the south. Most of the camp guards left Dachau and only light resistance was given to the U.S. Army troops that arrived on 29 April 1945. Near the camp, they found 30 railroad cars full of corpses. More bodies were found at the camp but there were 30,000 survivors, many who were emaciated. The scene was appalling to the American troops. Many would write or talk about it later as one of the most horrific things they had ever seen. 30 captured SS guards were killed by American soldiers over what they saw (others claim it is was a lot more). German citizens of Dachau were later forced to bury the 9,000 dead inmates found at the camp.
(Here is a video on the liberation, but you will need to view it on YouTube.)
Gilbert, Martin: The Holocaust-A History of The Jews of Europe During The Second World War, Henry Holt & Company, New York 1985
Snyder, Lewis: Encyclopedia of The Third Reich, Marlowe & Company, New York, 1976
United State Holocaust Memorial Museum: Historical Atlas of The Holocaust, Macmillan Publishing USA, New York 1996
Jewish Virtual Library