Before 1933 Frankfurt am Main was considered Germany’s most ‘Jewish’ city. After 1945 a new Jewish community was established. However, if it was to have a lasting future, it needed constant immigration. This article describes the particular situation in Frankfurt, where the US army established its European headquarters. Utilizing the Frankfurt example, it demonstrates that ‘Displaced Persons’ were integrated into the Jewish community without difficulty but that internal problems remained for a long time. The later immigration of Jews from Israel from the 1950s, too, helped to stabilize Jewish life and, at the same time, made it more complicated.