Simon Wiesenthal was liberated by the United States army from Mauthausen concentration camp in May 1945. Following liberation, he supported U.S. occupation forces in Linz with their search for former SS members as part of his work with the Jewish Historical Documentation (Jüdische Historische Dokumentation, JHD) in 1947. The JHD collected survivor testimonies, evidence on Nazi crimes, and corresponded with offices and private persons worldwide in an effort to locate Nazi criminals and collaborators in hiding.
After the closure of the JHD in 1954, Wiesenthal stayed with his family in Linz, where he worked for various Jewish and international organisations. As vice-president of the Jewish Community of Linz, Wiesenthal worked for the AJDC (Joint) and ORT (Organization for Rehabilitation through Training) in the refugee camps near Linz, which were reopened in the 1950s for Jewish and non-Jewish refugees from the Soviet Bloc. One such camp on the outskirts of Linz, Asten, was opened in 1956 for Jewish refugees from Hungary and Poland.
Wiesenthal moved to Vienna in 1961. In Vienna, he capitalised on the international renown he had obtained for his role in the capture of Adolf Eichmann, and refocused his efforts on finding war criminals and bringing them to justice. He opened a new documentation center in Vienna, the “Documentation Centre of the Association of Jewish Victims of the Nazi Regime” (“Dokumentationszentrum des Bundes Jüdischer Verfolgter des Naziregimes”, JDC), which he directed until his death.