The Caledonian Railway main line in Scotland connected Glasgow and Edinburgh with Carlisle, via Carstairs and Beattock.
It was opened in 1847 by the Caledonian Railway. The approach to Glasgow used railways already built, primarily for mineral traffic; these were later by-passed by a more direct route.
Today, the route forms the northern section of the West Coast Main Line, and was electrified in the early 1970s.