Washington, D.C., the capital of the United States, is a unique federal district and not part of any state. It is owned by the federal government of the United States. The land was originally donated by the states of Maryland and Virginia to create the capital. However, the portion that was donated by Virginia was returned in 1846, so now the district is entirely on land that was originally part of Maryland.
The federal government has jurisdiction over Washington, D.C., and it is governed by a mayor and a city council. However, Congress has the ultimate authority over the district and can overturn local laws. This unique arrangement means that while residents of Washington, D.C., pay federal taxes and can vote in presidential elections, they do not have voting representation in Congress.