The Mid-Atlantic is a region of the United States located in the overlap between the Northeastern and Southeastern states of the United States. Its exact definition differs upon source, but the region typically includes New Jersey, New York, and Pennsylvania, with other sources including or excluding other states or areas in the Northeast and Southeast, most common among them being Delaware, the District of Columbia, Maryland, Virginia, and West Virginia. The region has its origin in the Middle Colonies of the 18th century when its states were among the Thirteen Colonies of pre-revolutionary British America. As of the 2020 census, the region had a population of 60,783,913, representing slightly over 18% of the nation's population.