The states in the Mid-Atlantic region run from New York in the north along the Atlantic shore of the east coast, to the Potomac River in the south. All five of the states in this region were among the original thirteen colonies that fought for independence from Great Britain and later ratified the U.S. Constitution.

The Mid-Atlantic States were also the birthplace of the westward settlement movement and the Transportation Revolution (1816–1850). These two sweeping events led to the beginnings of the railway, steel, coal, oil, and canal-building industries. As a result, some of the largest and most heavily populated cities in the United States are in the Mid-Atlantic States. Cities such as New York City, Philadelphia, Buffalo, Pittsburgh, and Baltimore all boomed in part because of their location during the Transportation Revolution.