The United States Geological Survey recognizes 35,000 cities and towns within the U.S. To be recognized by the United States Geological Survey, a place simply has to have a permanent population and buildings. It does not have to be incorporated.
An unincorporated place is usually a location with a permanent population of less than 5,000. According to City Mayors, there are 19,429 municipal governments in the United States. Only those areas large enough to incorporate have municipal governments, so the amount of cities and towns in the United States large enough to incorporate is just under 20,000. If cities are counted based strictly on the population definition for a city, which is generally a place with 10,000 or greater permanent residents, then the number changes again. All municipalities with permanent populations between 5,000 and 10,000 must be removed. According to the United States Census Bureau, the number of towns or municipalities with fewer than 10,000 residents is about 31,000. That would mean that of the 35,000 cities and towns recognized by the United States Geological Survey, only 4,000 of them actually qualify as cities based on the term "city" as defined by population. It is estimated that about half of the United States population resides in a city or town with fewer than 25,000 people.