On August 8, 1938, the SS transferred prisoners from camp Dachau and began the construction of Mauthausen. Mauthausen was meant to reserved for prisoners with "bad records," criminals, and those who "could not be reeducated."

Most of the mother camp was completed by 1939. Within a 10 square kilometer area, Mauthausen was divided between quarry and camp. The main camp consisted of three sections with thirty blocks. Camp I included living quarters for inmates, a women's section, the sick block, and the maintenance facilities. Camp II contained five huts for inmate housing. Camp III had six huts for prisoners. There were also six large and eight small military tents added in 1944 for the Hungarian Jews.

Inside the camp housed the kitchen, the bunker, the crematorium, the hospital, and a double crematorium. The furnace room for the crematoria contained the execution corner. As the prisoners walked in and measured their height, the Nazis would shot them in the neck through a slot in the headboard. Gas chambers were built like bathrooms. Cyclone B streamed into the chamber when the prisoners anticipated for water. The officials actually used three types of gassing facilities. Running between Mauthausen and Gusen, a gas van converted from a railroad car killed thirty prisoners each way. The small chamber inside the camp included the execution room, the morgue, and the dissection room. Carbon monoxide was used often in this chamber to kill about 120 victims each time. Another gassing facility was the nearby Hartheim Castle. It was originally a home for the deranged. After converted into a gas chamber, it took the lives of Mauthausen prisoners. An estimation was made that between 1942 and 1945 approximately 10,000 prisoners were killed by gassing facilities.

Mauthausen was a camp for work. Most of the prisoners were worked to death instead of getting murder. The Nazis established sixty subcamps, including the big ones like the Gusen trio, Ebensee, and Melk. Subcamp work included a wide range of industries: iron ore mining, hydropower construction, road and tunnel construction; tank, aircraft engine, and plane manufacture; armament, cartridge, and V-weapon production. The Mauthausen Quarry was the most deadly place to work. It had harsh conditions and high death rate. The Nazis forbidden the prisoners to use any machine for work. Everything was done by bare hands. Workers there often died from starvation, tuberculosis, cold, heart attack, accidents, and murder.

In addition to the harsh working condition, prisoners in Mauthausen also suffered from murderous treatment by the Nazis. The Nazis developed a drowning murder method. They either forced hoses into the prisoner's mouth until the lungs burst from the water, immersed victims in barrels, or submerged them in ditches. Another brutal method they used was to force the prisoners out of their blocks, naked, and run on sharp stones.

Mauthausen participated in the system's medical experimentation program. Experiments were conducted on sterilization, castration, drug tests, heart injections, and special operations. Everyday, doctors would removed organs from living bodies and bottled the organs and stored them on the dissection room shelves.

Mauthausen was finally liberated by Patton's troops on May 8, 1945. Soldiers saw before their eyes not living human beings, but walking skeletons. The camp authorities at the Mauthausen museum estimated that more than 206,000 lived in Mauthausen proper and more than 110,000 perished as a result of living in the camp.