The Brunswick Southern Railway branch from Börßum to the Hanoverian Southern Railway at Kreiensen was built from 1853 and opened in 1856.
When the southwestern link from Kreiensen to Holzminden and Höxter link to the lines of the Royal Westphalian Railway Company opened in October 1865, a through route was established via Altenbeken to the Rhine-Westphalian industrial region.