What river is Washington, D.C. located on?

Washington, D.C. is located on the Potomac River, which forms part of the District's western and southern boundary.

The Potomac flows roughly 405 miles from the Potomac Highlands of West Virginia to Chesapeake Bay. Washington was deliberately established along the river because its location supported transportation, trade, and access to the interior. The river also passes landmarks closely associated with the capital, including Georgetown, the National Mall waterfront, and Mount Vernon farther south.

The Potomac is sometimes confused with the Anacostia River, which also flows through Washington, D.C. The Anacostia is an important tributary that joins the Potomac near Buzzard Point, but the Potomac is the principal river traditionally associated with the capital. The river has additional historical significance: the Union's Army of the Potomac was named after it during the American Civil War.