Washington, D.C., formally known as the District of Columbia is still commonly referred to as Washington or just D.C. This city is the capital of the United States of America. It was founded after the American Revolution and was set as the seat of government for the newly formed independent country. The City of Washington was named after the First President of the United States. Washington is the principal city of the Washington metropolitan area. The population of DC was 6,131,977 according to the 2010 US Census. Washington has been described as an important political capital, which status is undoubted because of its status as the capital of the United States federal government. It is one of the most visited cities in the whole world, harboring over 20 million tourists annually. As of the signing of the document known as the Residence Act on July 16, 1790, which approved the building of a capital district located along the Potomac River DC was created. The Constitution of the United States provided a section for a federal district which would be under the exclusive jurisdiction of the Congress therefore, the District is therefore not a part of any state. Two states, the states of Maryland and Virginia each donated a piece of land to form the federal district. This included the two pre- constitution settlements of Georgetown and Alexandria. The city was named in honor of President George Washington, and was founded in 1791 to serve as the new national capital. In the year of 1846, Congress returned the land originally which was ceded by Virginia. An in the year 1871, it created a single municipal government for the remaining portion of the District. As of 2017 Washington had an estimated population of 693,972. Commuters come from the surrounding VA and MD suburbs raise the city's daytime population to more than one million during the work week.