A metropolis is a large city or conurbation which is a significant economic, political, and cultural center for a country or region, and an important hub for regional or international connections, commerce, and communications. The term is Ancient Greek (μητρόπολις) and means the "mother city" of a colony, that is, the city which sent out settlers. This was later generalized to a city regarded as a center of a specified activity, or any large, important city in a nation.

The East Coast of the United States, also known as the Eastern Seaboard, the Atlantic Coast, and the Atlantic Seaboard, is the coastline along which the Eastern United States meets the North Atlantic Ocean. Regionally, the term refers to the coastal states and area east of the Appalachian Mountains that have shoreline on the Atlantic Ocean, from north to south, Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, New York, New Jersey, Delaware, Maryland, Virginia, North Carolina, South Carolina, Georgia, and Florida.

The world's first skyscraper was built in Chicago in 1885. Since then, the United States has been home to some of the world's tallest skyscrapers. New York City, specifically the borough of Manhattan, notably has the tallest skyline in the country. Eleven American buildings have held the title of tallest building in the world. New York City and Chicago have always been the centers of American skyscraper building. The 10-story Home Insurance Building, built in Chicago in 1885, is regarded as the world's first skyscraper; the building was constructed using a novel steel-loadbearing frame which became a standard of the industry worldwide.