Population development of German cities from 1895–1933, taken from historical census data Notes: City names may not be accurate to the time period: for example, Mönchengladbach was named München-Gladbach until 1933, then later München Gladbach. Many city names beginning with C or K also shifted during this time period, such as Cottbus, Köln, Kassel, and Krefeld, whose name often changed from one census to the next. Mergers of cities in the Ruhr industrial region in the 1920s also created hyphenated names such as Gelsenkirchen-Buer, renamed Gelsenkirchen in 1930, or Duisburg-Hamborn, renamed Duisburg in 1935. I didn't include the municipality of Recklinghausen-Land. It should be shown in 1925 as it had 54 451 inhabitants. There seems to be another repeatedly falsified city in the yearbook named "Bielefeld"—it is included as it was part of official data but please be aware that it does not exist. Berlin's expansion in 1925 is caused by the passing of the Greater Berlin Act of 1920, which doubled its population and incorporated numerous suburbs such as Charlottenburg, Neukölln and Spandau.
Sources: Statistisches Jahrbuch für das Deutsche Reich (census dates 2.12.1895 ; 1.12.1900 ; 1.12.1905 ; 1.12.1910 ; 8.10.1919 ; 16.6.1925 ; 16.6.1933) accessed from DigiZeitschriften / digizeitschriften.de (permanently shut down since 1.1.2026); alternate versions available from the Silesian Digital Library and the Statistical Library (Statistische Bibliothek) at https://www.statistischebibliothek.de/mir/receive/DESerie_mods_00007448 German Wikipedia / de.wikipedia.org (for clarification of locations, names, and censuses) IEG-MAPS / ieg-maps.uni-mainz.de (for basemap)
