I recently purchased the six copies of The Railway Magazine which were issued in 1948. The first of these coincided with the formation of British Railways, and the January/February 1948 issue of the magazine highlights for the readers a little of the history of railways in Britain which led up to that momentous occasion. The linked article below builds on the article in The Railway Magazine. http://rogerfarnworth.com/2019/12/09/british-railways-1948
When was nationalisation of the railways in Great Britain first promoted as a significant idea? Perhaps you'd like to fix a year in your mind before reading the linked post. http://rogerfarnworth.com/2020/01/23/british-railways-1948-part-2
