 Its main line was opened in stages between 1852 and 1853.When the West Midland Railway (WMR) was formed by amalgamation in 1860, the OW&WR was the dominant partner, but the West Midland company amalgamated with the Great Western Railway (GWR) in 1863.Several branches and extensions were built in the West Midlands, and the main line was developed as an important trunk route.