Glasgow's first mainline railway was the Garnkirk & Glasgow, opened in 1831. In the railway boom of the mid-1830s, three companies were formed to link Glasgow with Edinburgh, Greenock, Ayr and Kilmarnock. These lines opened in 1840-42, with the Greenock and Ayr lines sharing the route to Paisley. The "Railway Mania" of the mid-1840s resulted in the building of two lines to Carlisle and lines to Aberdeen and Dundee creating a skeleton of routes, with links to England. Amalgamations between 1850 and 1866 created three large companies in central Scotland, all serving Glasgow. In the mid-1870s the Caledonian and Glasgow & South Western railways both built extensions to new stations in the city centre, Central and St Enoch. The North British Railway rebuilt Queen Street Station.
During the 1880s and 1890s several important suburban lines were built: the Cathcart District Railway; the east-west Glasgow City & District and Glasgow Central railways; rival routes operated by the North British and Caledonian railways; and the underground Glasgow District Subway. The three mainline railways also competed for the Clyde Coast steamer traffic, with new rail-linked steamer piers at Greenock, Gourock, Craigendoran and Ardrossan. Both Central and St Enoch stations were enlarged at the turn of the century to handle increasing traffic. Further development of the suburban system was curbed by competition from the electrified tramway system.
The railways during this period made the growth of Glasgow possible, bringing coal, building and other raw materials, and food-stuffs in - and taking away a wide range of manufactured goods. Later developments allowed the city to expand. Railways were at the heart of the creation of the extraordinary nexus of heavy and other industries in west central Scotland.