Under the 1790 Residence Act, which city became the permanent U.S. capital in 1800?

Under the 1790 Residence Act, Washington, D.C., became the permanent U.S. capital in 1800.

The act, signed by President George Washington on July 16, 1790, selected a site along the Potomac River for a permanent seat of government. It also made Philadelphia the temporary capital while the new federal city was planned and built. The location resulted from the Compromise of 1790, which connected the capital question with federal assumption of state debts.

The new district was surveyed and designed during the 1790s. Pierre Charles L’Enfant created the city plan, while James Hoban designed the President’s House, later known as the White House. The federal government moved from Philadelphia to Washington in 1800, although construction continued for years. Washington, D.C., is a federal district rather than a state, and Congress retains constitutional authority over it.