United States (U.S.), officially United States of America (U.S.A.), commonly referred to as America, is a federation of a federal republic consisting of fifty states*, one district, and various territories.

The contiguous United States or officially the conterminous United States consists of the 48 adjoining states* (plus Washington, D.C.) on the continent of North America. The terms exclude the non-contiguous states of Alaska and Hawaii, and all off-shore insular areas.