Notes:  By the end of this period England had an extensive, albeit sparse, railway network. The South-eastern Railway (SER) had almost reached Dover (and the Continent), in uneasy alliance with the London, Brighton & South Coast Railway (LBSCR), who had built the only southbound route out of London, to Brighton, that Parliament would approve. To their west, the London & South-western Railway (LSWR) had reached Southampton, which they developed as an important port, and Gosport, for the ferry to Portsmouth. To the west of London, Brunel's Great Western Railway (GWR), opening from 1838, had reached Bath and Bristol and was already approaching Exeter. Main lines from Euston to Birmingham, and Birmingham to Warrington laid the foundation of the modern West Coast Mainline, the initial cross-over junction on the Liverpool & Manchester being rapidly replaced by direct branches to Liverpool and Manchester from Crewe. A roundabout route connected Manchester and Leeds across the Pennines, and Leeds was also the end of the Midland Railway, which also connected Sheffield, Derby, Leicester and Nottingham to London, via an unsatisfactory change of train at Rugby. In Scotland, Edinburgh, Glasgow and Ayr gained their first connecting rail links.