Examples of the first class can be found in a handful of states and the District of Columbia:
Louisiana has no counties. Their parishes are, for all legal purposes, the equivalents of the counties found in 48 of the 49 other states.
In Virginia, all municipalities incorporated as cities are legally independent of any county that would otherwise contain them. However, Virginia also has traditional counties as found in virtually all other states. As all parts of Virginia are located in either a county or an independent city, Virginia's independent cities are considered county-equivalents.
Alaska is unique in several respects. The unit of government directly below the state level is called a borough instead of a county. Although the city of Anchorage is legally called the Municipality of Anchorage, it is considered a consolidated city and borough under state law. All of Alaska's boroughs except the so-called Unorganized Borough (see below) are considered county-equivalents.
Washington, D.C., like the capitals of many other countries (see below), has a special status. It is not part of any state; instead, it comprises the entirety of the District of Columbia, which, in accordance with Article 1, Section 8 of the U.S. Constitution, is under the jurisdiction of the U.S. Congress. When founded, the District was in fact divided into two counties and two independent cities. Alexandria County (which now forms Arlington County and a portion of the independent city of Alexandria) was given back to Virginia in 1846, while the three remaining entities (the City of Washington, Georgetown City and Washington County) were merged into a consolidated government by an act of Congress in 1871 and Georgetown was formally abolished as a city entity by another act in 1895. Congress has established a home-rule government for the city, although city laws can be overridden by Congress which has occurred even in recent years. Other than the lack of representation in Congress for its citizens, the city operates much like other independent cities in the United States, although technically, it does not meet the legal definition of one. In all respects, however, the US media does treat Washington D.C. as an independent city.
The second class of county-equivalents is unique to Alaska. Most of the land area of that state has no organized county-level government. The Alaska state government calls the entire portion of the state that is not part of a borough the Unorganized Borough. In 1970, the Census Bureau, in cooperation with the state, divided the Unorganized Borough into census areas for statistical purposes. Each census area is considered a county-equivalent.
As of the 2000 census there were a total of 3,141 county-equivalents in the United States. The current total is 3,140, resulting from the decision of Clifton Forge, Virginia to relinquish its city charter in 2001 and reincorporate as a town within Alleghany County.