Editor's note: Federal Railroad Administration has provided details on the derailed CSX train cars in Washington, DC. They reported that five of the 15 derailed were tank cars. Of these five, one tank car was loaded sodium hydroxide. Some content leaked through one or more of the car's bottom valves. The leak has since been sealed and the car remains at the site. One legacy DOT111 tank car, which derailed onto its side, was transporting ethanol. The car is intact with no breaches but had a minor leak that has since been contained, NBC News reports. One of the cars was an empty, residue liquid petroleum gas tank car, which did not breach. The two other tank cars were loaded with non-hazardous calcium chloride. One of them leaked but has been sealed. We will continue to provide updates on the situation. - Imana
Washington, D.C., formally the District of Columbia and commonly referred to as "Washington", "the District", or simply "D.C.", is the capital of the United States. The signing of the Residence Act on July 16, 1790, approved the creation of a capital district located along the Potomac River on the country's East Coast. The U.S. Constitution provided for a federal district under the exclusive jurisdiction of the Congress and the District is therefore not a part of any U.S. state.
The states of Maryland and Virginia each donated land to form the federal district, which included the pre-existing settlements of Georgetown and Alexandria. Named in honor of George Washington, the City of Washington was founded in 1791 to serve as the new national capital. In 1846, Congress returned the land originally ceded by Virginia; in 1871, it created a single municipal government for the remaining portion of the District.
Washington had an estimated population of 672,228 as of July 2015. Commuters from the surrounding Maryland and Virginia suburbs raise the city's population to more than one million during the workweek. The Washington metropolitan area, of which the District is a part, has a population of over 6 million, the seventh-largest metropolitan statistical area in the country.
The centers of all three branches of the federal government of the United States are in the District, including the Congress, President, and Supreme Court. Washington is home to many national monuments and museums, which are primarily situated on or around the National Mall. The city hosts 176 foreign embassies as well as the headquarters of many international organizations, trade unions, non-profit organizations, lobbying groups, and professional associations.
A locally elected mayor and a 13‑member council have governed the District since 1973. However, the Congress maintains supreme authority over the city and may overturn local laws. D.C. residents elect a non-voting, at-large congressional delegate to the U.S. House of Representatives, but the District has no representation in the U.S. Senate. The District receives three electoral votes in presidential elections as permitted by the Twenty-third Amendment to the United States Constitution, ratified in 1961.