Not all the railways were merged into one of the big 4 railways. One that survived the 1923 grouping was the Midland & Great Northern Joint Railway which prior to the grouping was joined tly owned by the Midland Railway and the Great Northern Railway. The Midland became part of the LMS whilst the GNR became part of the LNER, but the M&GNR remained separate to both until the nationalisation in 1948. Apart from that, it was a good summation. We continued with steam when the writing was on the wall for steam power because we had lots of coal and very little oil beneath the country.