In 1846 three companies, London & Birmingham, Grand Junction Railway and Manchester & Birmingham amalgamated to form the London & North Western Railway. The amalgamation created 247 miles of railway that linked London, Manchester, Birmingham, Liverpool and Preston.

The London & North Western Railway continued to expand and by 1868 the company had added links to Oxford, Cambridge, Leeds, Swansea and Cardiff. However, attempts to amalgamate with Midland Railway ended in failure. By 1871 the London & North Western Railway employed 15,000 people.