1864, but the old line remained for southbound freight. The Princeton Branch opened May 29, 1865, on which date passenger trains stopped running over the old line. The old line was removed between Trenton and Princeton in July; a portion in Trenton was kept to serve businesses. The Princeton–Kingston section was removed in September when freight operations began on the Princeton Branch; track north of Kingston (which was not next to the canal) was retained to serve the Rocky Hill Railroad. Competition Closely tied to the early NJRR was the Paterson and Hudson River Railroad (P&HR), later the main line of the Erie Railroad. The P&HR agreed in June 1833 to build to the west side of the New Jersey Palisades at Marion Junction, where it would use the NJRR's Bergen Hill Cut the rest of the way to the Hudson River. The P&HR opened November 29, 1833, prior to the opening of any part of the NJRR, in the meantime using a stagecoach along the Newark Turnpike to reach the river. A trackage rights agreement was made October 10, 1834, and P&HR operation to Jersey City began October 20. The Long Dock Tunnel opened April 15, 1861, giving the P&HR (by then part of the Erie) its own route to the Hudson River. Also involved with the NJRR was the Morris and Essex Railroad (M&E), later the Delaware, Lackawanna and Western Railroad's (DL&W) main line. On October 21, 1836, the NJRR agreed to carry M&E traffic between Newark and Jersey City, beginning on November 19. A new alignment meeting the NJRR in Harrison opened August 5, 1854. On October 14, 1863, the M&E began using the Long Dock Tunnel. The Central Railroad of New Jersey (CNJ) also used the NJRR to reach Jersey City from Elizabeth until its own line opened on August 1, 1864. The C&A often used legislative and legal means to protect its monopoly on New York City-Philadelphia travel. The monopoly was finally broken on May 1, 1876, with the completion of the National Railway, over seven years after the legal monopoly expired. On January 19, 1831, New Jersey passed a supplement to the D&R Canal's charter, allowing them to build a railroad alongside their canal. However, this was soon mooted by the union between the C&A and D&R. On February 15, 1831, the C&A and D&R were combined as the Joint Companies, with all important