 The parts that were later included in the PRR main line opened from Philadelphia to Malvern (the end of the West Chester Railroad) in 1832 and Malvern to Lancaster in 1834.A short piece of the Allegheny Portage Railroad in East Taylor Township and Conemaugh Township, including the Portage Viaduct over the Little Conemaugh River, later became part of the PRR main line; it was opened in 1834.The Harrisburg, Portsmouth, Mountjoy and Lancaster Railroad opened from Harrisburg southeast to Middletown and from Lancaster northwest to Rheems in 1836.