The territory that became the original District of Columbia was formed from land along the Potomac River that the states of Maryland and Virginia ceded to the federal government of the United States in accordance with the 1790 federal Residence Act and later legislation. The territory was a square that measured on each side, totaling (see: Founding of Washington, D.C.). Ellicott's team placed boundary marker stones at or near every mile point along the borders of the new capital territory (see: Boundary markers of the original District of Columbia).