Was it common to find foreigners in Germany during Weimar Republic and the beginning of the Nazi regimes?
Because they do not seem particularly attractive historical periods but I found many statistics reporting separated figures for foreigners but no direct data of the presence of foreign people on German soil (censuses or other).
Do you have any insight by yourselves or are you aware of sources I can use to find more data about that?
The number of foreigners, broken down by nationality, was recorded in the 1925 and 1933 censuses. Technically, the 1933 census falls just after the fall of the Weimar Republic, being taken in December 1933, but still comes within your timeframe.
A further census was taken in 1939, although that also included the territories of Austria, Sudetenland and Memelland.
The totals for the 1925 census are included as tables and in graphical format in this article on German Migration as figure 2.
A fairly complete dataset of foreigners in Germany, covering the whole period from 1834 to 2010, is available to download as an Excel worksheet from the site's associated data (03_Migration.xls).
