The United States, officially the United States of America, is a 50-state federal republic. Aside from the 48 contiguous states that comprise the continent’s main latitudes, the United States includes the state of Alaska, at North America’s northernmost extremity, and the island state of Hawaii, in the mid-Pacific Ocean. 

The conterminous states are bound by Canada on the north, the Atlantic Ocean on the east, the Gulf of Mexico and Mexico on the south, and the Pacific Ocean on the west. The United States is the world’s fourth largest country by land area (after Russia, Canada, and China). The national capital is Washington, which is coextensive with the District of Columbia, which was established as the federal capital region.