This might be new information to some. As ever, apologies if it isn't.
In all the writings about the War that are appearing in connection with the 90th anniversary, the usual frequent mentions of the significance of railways are made. I began wondering when railways were first put to military use, and found this highly informative article.
The first use of a train to move troops was on the day the first train ran. And I was surprised to discover the year in which troops were taken directly to the front by train.
"Sometimes things that are not true are included in Wikipedia. While at first glance that may appear like a very great problem for Wikipedia, in reality is it not. In fact, it's a good thing." - Wikipedia.
The Duke of Wellington had mixed views on railways (as they might encourage masss movement of the population which on the whole he thought a bad thing) but grudgingly approved (as he could see the advantage of being able to move troops quickly) He ordered barracks to be built close to all major termini and junctions so that in a national emergency the army could both use the railways and control them.
Just one correction. "The first use of a train to move troops was on the day the first train ran" is wrong. The train pulled by the Rocket was far from the first to run. Trains were running on other lines in Britain some years previously to this. Contarary to some popular misconceptions Stephenson did not invent the steam locomotive.