Complex sentence: The Great Northern Railway continued to serve the Cavan and Leitrim Railway, however in 1959 all services along the remaining rail lines were terminated and the stations along their routes were closed.
Split into simpler sentences: The Great Northern Railway (G.N.R.) continued to serve the Cavan and Leitrim Railway. However, in 1959 all services along the remaining rail lines were terminated and the stations along their routes were closed.