The answer depends on how one defines a “city.” By definition, a city is a large gathering of humans or a large town.
What’s the difference between a town and a city? A town is typically an unincorporated community with no governmental powers and services provided by the county government. A city is an incorporated community with governmental powers delegated by the state or county and services provided by the city government.
Countries around the world have minimum population sizes for an area to be considered “urban,” or a city. In the U.S., this is 2500. According to the U.S. Census Bureau, about 80% of the United States population lives in urban areas.
Furthermore, cities are split into small cities, medium cities, large cities, metropolises, conurbations, and megalopolises. Small cities, also known as boroughs, have populations below 100,000 and function as a municipality or subdivision of a city. Medium cities are between 100,000 and 300,000 people and have abundant services but not all. Large cities have populations between 300,000 and 1 million and many services. Metropolises are a large city and its suburbs have 1 to 3 million people. Conurbations are a group of metropolises that have 3 to 10 million people. Megalopolises are a group of conurbations with populations of 10 million or more.
As of 2018, there are 19,495 incorporated cities, towns and villages in the United States. 14,768 of these have populations below 5,000. Only ten have populations above 1 million and none are above 10 million. 310 cities are considered at least medium cities with populations of 100,000 or more.
The largest city in the U.S., and is part of the Northeast megalopolis, is New York City with a population of 8.5 million people. New York City has five boroughs: Manhattan, the Bronx, Brooklyn Queens, and Staten Island. New York City is also the largest metropolitan area in the world by urban area (4,585 square miles) and by population by both Metro Statistical Area (20.3 million) and combined statistical area (23.7 million).
As of 2018, 127 million people, about 40% of the U.S. population, lived in cities with 50,000 or more residents. As the population begins to move more towards urban areas, the number and size of cities in the United States will continue to grow.