With a loan of 1000 thaler from his father and with the help of his two sisters, Karstadt opened his first store, ″Tuch-, Manufaktur- und Konfektionsgeschäft" at the Krämerstr. 4 in Wismar on 14 May 1881. By 1920 he owned over 30 shops across Germany. The Karstadt Warenhaus AG, which is what his chain of stores was called by 1920, continues as Arcandor.
- "14. Mai 2006 - Vor 125 Jahren: Rudolph Karstadt eröffnet sein erstes Geschäft". Westdeutscher Rundfunk (in German). Retrieved 24 February 2013.