Mid-Atlantic (United States)

The Mid-Atlantic is a region of the United States located in the eastern part of the country. Traditional definitions include seven U.S. states: New York, New Jersey, Pennsylvania, Delaware, Maryland, Virginia, West Virginia, and the national capital of Washington, D.C.

Depending on various factors, different regional divisions exist however: the U.S. Bureau of Labor Statistics in its newest regional division excludes New York from the region; the U.S. Census Bureau excludes Delaware, Maryland, Virginia and West Virginia from the region; USGS defines the region by watersheds thus additionally including North Carolina; the EPA excludes both New York and New Jersey; the U.S. Maritime Administration excludes upper New Jersey and New York; the Office of Small Business Programs of the U.S. Department of Defense excludes New York. When discussing climate, Connecticut is sometimes included, since its climate is closer to the Mid-Atlantic than the rest of the New England region.

The Mid-Atlantic region played an instrumental and historic role in the nation's founding and the development of the nation. Six of the seven states were members of the Thirteen Colonies that sent delegates to the Second Continental Congress, which assembled in Philadelphia and unanimously adopted the Declaration of Independence, and formalized the Continental Army under George Washington's command during the American Revolutionary War. Following independence, the states again gathered in Philadelphia at the Constitutional Convention, in 1788, where they ratified the United States Constitution, which remains the oldest and longest-standing written and codified national constitution in force in the world.

As of the 2020 census, the region had a population of 60,783,913, representing slightly over 18% of the nation's population. The Mid-Atlantic is a relatively affluent region of the nation; nearly half of the nation's 100 highest-income counties based on median household income are located in the Mid-Atlantic, and 33 of the nation's top 100 counties based on per capita income are in the region. Most of the Mid-Atlantic states rank among the 15 highest-income states in the nation by both median household income and per capita income.

The Northeast Corridor and Interstate 95 in the region link an almost contiguous urban region, which includes large and small cities and their respective suburbs and forms the Northeast megalopolis, one of the world's most important concentrations of finance, media, communications, education, medicine, and technology.

The region is home to eight of the top 25 ranked universities in the nation: Cornell University in Ithaca, New York; Columbia University in New York City; Princeton University in Princeton, New Jersey; the University of Pennsylvania in Philadelphia; Carnegie Mellon University in Pittsburgh; Johns Hopkins University in Baltimore, Georgetown University in Washington, D.C.; and the University of Virginia in Charlottesville, Virginia according to U.S. News & World Report Best Colleges Ranking.