What is the only capital in US that not a state?

Washington, D.C. is the capital of the United States, but it is not a state. It is a federal district, which means that it is under the direct control of the federal government. The District of Columbia was created in 1790, and it was named after George Washington, the first president of the United States. Washington, D.C. is home to the White House, the Capitol Building, and the Supreme Court of the United States.