As the nation's capital and de facto capital, Washington, D.C. (officially the District of Columbia) is sometimes referred to as Washington or just D.C. It is situated on the east bank of a Potomac River, which defines its southwestern and southern borders with the United States, state of Virginia, and has a land boundary with the state of Maryland on its remaining sides. It is also the capital of the State of Virginia. Although both the city and the federal district are named after George Washington, a Founding Father and the first president of the United States, the city is called after Columbia, a feminine personification of the country. The city is an important global political centre since it serves as the headquarters of the United States federal government and various international organisations. Over 20 million people visited it in 2016, making it one of the most popular tourist destinations in the United States.
In accordance with the United States Constitution, a federal district exists under the sole authority of Congress; as a result, the district does not constitute a part of any one state in the United States (nor is it one itself). A capital district along the Potomac River on the country's East Coast was officially established on July 16, 1790, with the signature of George Washington. After being established in 1791 to serve as the nation's capital, Washington became the site of the first meeting of Congress, which took place there in 1800. After being designated as a federal district in 1801, the region, which had previously been a part of Maryland and Virginia (and included the communities of Georgetown and Alexandria), was formally acknowledged as such in 1802. A single municipal administration was established for the remainder of the district in 1871, after Congress restored the area originally granted by Virginia, including the city of Alexandria, in 1846. Since the 1880s, there were efforts to turn the city into a state, a movement that has gathered strength in recent years, and a statehood bill passed the House of Representatives in 2021.
It is divided into quadrants based on the Capitol Building, and there are as many as 131 neighbourhoods in the city overall. Approximately 689,545, according to the 2020 Census, places it as the 20th-most populated city in the United States and gives it a population bigger than that of two U.S. states: Wyoming and Vermont, according to the Census Bureau. Commuters from the neighbouring Maryland and Virginia suburbs contribute to the city's daytime population reaching more than one million during the weekday working day. 6.3 million people lived in the Washington metropolitan area in 2019, which was the sixth-largest in the US (it includes portions of Maryland, Virginia, and West Virginia). Washington is the nation's capital.
It is home to all three departments of the United States federal government: the legislative branch of Congress, the executive branch of the president, and the Supreme Court of the United States of America (judicial). Many national monuments and museums may be found on and around the National Mall in Washington, most of which are located on or near it. It is home to 177 foreign embassies and the headquarters of a slew of international organisations, trade unions, non-profits, lobbying groups, and professional associations, among them the World Bank Group, the International Monetary Fund, the Organization of American States, the AARP, the National Geographic Society, the Human Rights Campaign, the International Finance Corporation, and the American Red Cross, among others.
In the district since 1973, a mayor and council comprised of 13 members are chosen by the people. The United States Congress retains ultimate jurisdiction over the city and has the right to overrule municipal ordinances if necessary. DC residents elect a non-voting, at-large congressional delegate to the United States House of Representatives, but the district does not have any representation in the United States Senate. According to the Twenty-third Amendment to the United States Constitution, which was enacted in 1961, district voters choose three presidential electors.