Thuringian Railway
Until the completion of the Frankfurt–Bebra line in 1866, all express trains between Frankfurt and Berlin ran on the Main–Weser Railway. These trains ran on to the Frederick William Northern Railway at Guntershausen to connect with the Thuringian Railway. Express trains continued to run from Frankfurt to Berlin via Kassel until the end of World War II. In the following years of the American occupation trains also ran on this route.