Delaware (river)

Delaware (river), river in the eastern United States, one of the major rivers of the region. The Delaware rises on the western slopes of the Catskill Mountains in eastern New York. At that point, the river consists of two branches: the West Branch and the East Branch. The West Branch is the chief branch; it flows southwest as far as Deposit, New York, and then turns southeast. From a point near Hale Eddy, New York, to Hancock, New York, it forms the boundary between Pennsylvania and New York. The East Branch parallels the course of the West Branch above Deposit. The two branches meet at Hancock. From this point, the Delaware, flowing southeast, continues as the New York-Pennsylvania boundary as far as Port Jervis, New York. There it becomes the boundary between Pennsylvania and New Jersey, following a generally southern course to its outlet in Delaware Bay. The lower Delaware forms the boundary between New Jersey and Delaware for a few miles.

Important tributaries of the Delaware include the Neversink, Calicoon, and Mongaup rivers in New York; Lehigh, Schuylkill, and Lackawaxen rivers in Pennsylvania; and the Maurice and Musconetcong rivers in New Jersey. The West Branch flows for 145 km (90 mi) and the East Branch flows for 121 km (75 mi). It is 451 km (280 mi) from the junction of the two branches to Delaware Bay. The Delaware River drains an area of 31,000 sq km (12,000 sq mi).

The Delaware is a source of hydroelectric power and an important waterway. It is navigable by large, oceangoing vessels as far inland as Philadelphia and by smaller vessels to Trenton, New Jersey. A canal once connected Trenton to New Brunswick, New Jersey, on the Raritan River. The canal has been filled in at numerous points, such as Manville and New Brunswick. The Chesapeake and Delaware Canal connects the Delaware River below Wilmington, Delaware, with Chesapeake Bay. The canal is navigable by oceangoing vessels. Through the Delaware River Basin Commission, created in 1961, the federal government and the four Basin states—New York, Pennsylvania, New Jersey, and Delaware—jointly manage Basin assets and problems.

Sections of the Delaware River are particularly scenic. These sections include the Catskills between New York and Pennsylvania, known as the Upper Delaware, and the area between New Jersey and Pennsylvania that makes up the Delaware Water Gap National Recreation Area.

On the evening of December 25, 1776, George Washington led his troops across the Delaware. The next day, he and his troops defeated German mercenaries allied with the British (Hessians) in the Battle of Trenton.