English: What is now Amtrak’s Northeast Corridor, an uninterrupted railroad route from Boston to Washington, D.C., was completed by the creation of a system that connected the Pennsylvania Railroad and the New Haven Railroad. Constructed over about a decade and a half, the system included Manhattan Transfer station, the New York Tunnel Extension, Pennsylvania Station, the New York Connecting Railroad, and the Hell Gate Bridge. At its southern end, it branched off about two miles above Newark on the Pennsylvania Railroad’s existent line to ferry slips on the New Jersey shore. At its northern end, it connected to the Harlem River and Port Chester Railroad and via that to the New Haven line at a point just below New Rochelle station. With the opening of the Hell Gate Bridge in 1917, the system was complete. The map that has been marked here may be viewed at https://www.flickr.com/photos/internetarchivebookimages/14760827942/ and is from page 583 of Electric Railway Journal (1908). It would seem to be in the public domain. The markings are my own.