 It is a key section of the route that later became known as the Portsmouth Line.The LBSCR had served Epsom since 1847, from via and (the Croydon and Epsom Railway), with ambitions to extend further west.But the LSWR wanted a share of the lucrative race traffic, and to this end it supported a proposed Wimbledon and Dorking Railway (WDR), connecting the named towns via Epsom.