The Pennsylvania Railroad, legal name The Pennsylvania Railroad Company, also known as the "Pennsy", was an American Class I railroad that was established in 1846 and headquartered in Philadelphia. It was named for the commonwealth in which it was established. At its peak in 1882, the Pennsylvania Railroad was the largest railroad, the largest transportation enterprise, and the largest corporation in the world.

The Main Line of Public Works was a package of legislation passed by the Commonwealth of Pennsylvania in 1826 to establish a means of transporting freight between Philadelphia and Pittsburgh. It funded the construction of various long-proposed canal and road projects, mostly in southern Pennsylvania, that became a canal system and later added railroads. Built between 1826 and 1834, it established the Pennsylvania Canal System and the Allegheny Portage Railroad.