The story
The Ashton, Stalybridge and Liverpool Junction Railway had always been closely aligned to the Manchester and Leeds Railway (M&LR), and in 1846 amalgamation was decided upon, also to include the authorised but unbuilt Wakefield, Pontefract and Goole Railway. The M&LR was vigorously extending its area of influence, and its original name was inappropriate, so as part of the amalgamation, a change of name was made: the combined company was to be the Lancashire and Yorkshire Railway. The amalgamation and the change of name were confirmed by the Manchester and Leeds Railway Act (No. 3) 1847 (10 & 11 Vict. c. clxiii) of 9 July 1847.
From Wikipedia’s article on Ashton, Stalybridge and Liverpool Junction Railway, shared under CC BY-SA 4.0.3