when was the capital moved to washington dc
History of Washington, D.C. On December 23, 1788, the Maryland General Assembly passed an act, allowing it to cede land for the federal district. The Virginia General Assembly followed suit on December 3, 1789.[18] The signing of the federal Residence Act on July 16, 1790, mandated that the site for the permanent seat of government, "not exceeding ten miles square" (100 square miles), be located on the "river Potomack, at some place between the mouths of the Eastern-Branch and Connogochegue".[19][20] The "Eastern-Branch" is known today as the Anacostia River. The Connogocheque (Conococheague Creek) empties into the Potomac River upstream near Williamsport and Hagerstown, Maryland. The Residence Act limited to the Maryland side of the Potomac River the location of land that commissioners appointed by the President could acquire for federal use.[19]