In spite of its initial promotion and capital subscription being largely English, the Caledonian Railway became the most Scottish of the pre-grouping companies: its blue locomotives reflected the Saltire, and its adoption of both the “Lion of Scotland” and the Royal Arms of Scotland as the Company Coat of Arms meant that these appeared on everything from locomotives and carriages to buildings, timetables, stationery, and hotel crockery. 

By choosing the historic Roman name for the country, were the early promoters declaring their intention that it was to be the National Railway of Scotland? It is interesting to note that in Joseph Locke’s report of 18 June 1842, the line from Lancaster to Carlisle is referred to as Part 1 of the Caledonian Railway and the line from Carlisle to Glasgow as Part 2.

The Caledonian Railway Company was incorporated by the Caledonian Railway Act of 1845. The first section of the railway between Carlisle and Beattock was opened on 10 September 1847. The line was completed to Glasgow and Edinburgh on 15 February 1848 and to Greenhill / Castlecary on 7 August 1848, where it joined the Scottish Central Railway. The line to Glasgow utilised the earlier railways Glasgow, Garnkirk & Coatbridge, and the Wishaw & Coltness, which it purchased in 1846 and 1849 respectively.

Between 1849 and 1864 the company repeatedly tried to absorb the Edinburgh & Glasgow Railway Co. into the Caledonian system. If it had succeeded the Caledonian would have had a virtual monopoly of Scottish Railways.

The full commercial complexity of the lines owned, leased, operated and used under running powers by the Caledonian Railway has never been fully explained by historians. The original lines from Carlisle to Garriongill, where they met existing lines for access into Glasgow, and the branch from Carstairs to Edinburgh, were expanded on three broad fronts.

The first was the growth of a maze of branch lines in central Scotland to meet the ever-growing demand for coal and iron to fuel the growth of the heavy engineering and shipbuilding industries, the products of which Scotland fed to the world. The second front of expansion was the lines to the steamer piers of Ardrossan, Wemyss Bay, Gourock and Oban, with the parallel development of the Caledonian Steam Packet fleet of steamers. The third front of expansion was the amalgamation and absorption of other lines, the largest being the Scottish Central in1865 and the Scottish North Eastern in 1866; by this means the Caledonian extended its line of rails to Aberdeen. 

The Forth and Clyde Navigation, started in 1768 along with the Docks at Bowling and Grangemouth, were amalgamated with the Caledonian Railway Company in 1867. The docks at Grangemouth were progressively developed into one of the largest and best-equipped ports in the UK.

From the moment of its conception the Caledonian was in competition, notably involving the battle of the routes via Annandale or Nithsdale, and the fights to take over the Edinburgh & Glasgow Railway and the Monklands Railway: both these companies were lost to the North British. On the Clyde, the competition between the steamer services has been well documented, as has the story of the “Races” from London to Edinburgh in 1888 and to Aberdeen in 1895. The strategic development and commercial success of the Company was much influenced by the alliance between the North British and the Glasgow & South Western Railway, originally designed to “stop the Annandale line”.  This grouping of its main competitors originated even before the Caledonian was incorporated and was to last the life of the Company until 1923. However the legacy of the Caledonian from this competitive environment were the development of locomotives and rolling stock well suited to the traffic needs, an excellent service to the public in both style and comfort, and a company more than willing to promote its own image.

The Caledonian Railway also operated a number of lines that it did not own. Among them were the Callander & Oban and the Lanarkshire & Ayrshire Railways.

The development and operation of the separate and independent Caledonian Steamer Packet Company's fleet of steam ships on the Clyde was as dynamic and colourful as the development of the railway itself and was operated in conjunction with special fast Boat Trains.

The Company also owned two very fine hotels as part of the stations at Glasgow Central and Edinburgh Princes Street. The development of the majestic hotel and golf course at Gleneagles was interrupted by WW1 and was not fully completed until after the grouping.

Glasgow Central as rebuilt 1900 -1907 was, and is still today, considered to be one of the finest stations in the UK, while Wemyss Bay station and pier was quite special, both in its functionalism and in its simple and compelling design. Many of the humbler stations also had an architectural merit which reflected a company proud of its image and reputation.

With one of the most severely graded mainlines in Britain and an ever increasing train load, the company had a continuing requirement for reliable and powerful locomotives. With Drummond and McIntosh as locomotive superintendents the Caledonian locomotive acquired legendary status.

Whatever the role, from the simplest pug shunting engine to the crack mainline express, the Caledonian had an appropriate class of locomotive. When the CR became part of the LMS in 1923 the stock of 1070 locomotives spread throughout the tracks of the newly formed LMS Northern Division.

The long term worth of the Caledonian locomotives is defined by the fact that over the first 10 years of the LMS ownership, despite the intense drive towards standardisation, only 137 or 13% of the Caledonian locomotives were scrapped compared to 36% Highland, 80% G&SW, 40% LNWR and 41% Midland.

The LMS inherited 3,040 Coaching, 51,536 Freight and 1,786 Service vehicles and 1,114 route miles from the Caledonian Railway. Many of the carriage designs such as the Grampians had been at the leading edge for style and comfort at the time of their introduction. The Caledonian was also one of the first of the UK companies to introduce Pullman coaches.

The company was grouped with the Glasgow & South Western Railway, the Highland Railway, the London & North Western Railway, the Midland Railway and a number of smaller railways across Scotland and England to form the London, Midland & Scottish Railway Co in 1923. This company was nationalised as part of British Rail in 1948.