The Stockton and Darlington Railway was the world's first permanent steam locomotive public railway. The line was 26 miles long, and was built between Darlington and Stockton-on-Tees and from Darlington to several collieries near Shildon. The S&DR proved a huge financial success, and paved the way for modern rail transport. Despite this, the S&DR was absorbed into the North Eastern Railway in 1863, which itself merged into the London and North Eastern Railway in 1922.