In 45 of the 50 states of the United States, the county is used for the level of local government immediately below the state itself. Louisiana uses parishes, and Alaska uses boroughs. In Connecticut, Massachusetts, and Rhode Island, some or all counties within states have no governments of their own; the counties continue to exist as legal entities, however, and are used by states for some administrative functions and by the United States Census bureau for statistical analysis. There are 3,242 counties and county equivalent administrative units in total, including the District of Columbia and 100 county-equivalents in the U.S. territories.
There are 41 independent cities in the United States. In Virginia, any municipality that is incorporated as a city legally becomes independent of any county. Where indicated, the statistics below do not include Virginia's 38 independent cities.
In Alaska, most of the land area of the state has no county-level government. Those parts of the state are divided by the United States Census Bureau into census areas, which are not the same as boroughs. The state's largest statistical division by area is the Yukon–Koyukuk Census Area, which is larger than any of the state's boroughs. Although Anchorage is called a municipality, it is considered a consolidated city and borough.
There are 100 county-equivalents in the territories of the United States: they are the 3 districts and 2 atolls of American Samoa, all of Guam (Guam as one single county-equivalent), the 4 municipalities in the Northern Mariana Islands, the 78 municipalities of Puerto Rico, the 3 main islands of the U.S. Virgin Islands, and the 9 islands in the U.S. Minor Outlying Islands.[1][2][3] All of these territorial county-equivalents are defined by the U.S. Census Bureau.