Arizona is part of the Western and the Mountain states in the southwestern region of the United States. It is the sixth largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix with the surrounding areas of Scottsdale, Mesa, Tempe, Chandler and Glendale on the west side. Arizona is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912.
Arizona is one of the Four Corners states bordering in the North with Utah, Colorado and with New Mexico along the eastern side. Nevada borders and California have one point in common southwest. Arizona's border with Mexico is 389 miles (626 km) long, on the northern border of the Mexican states of Sonora and Baja California.
Historically part of the territory of Alta California in New Spain, it became part of independent Mexico in 1821. Mexico ceded much of this territory to the United States in 1848 after being defeated in the Mexican–American War. Most of the southern portion of the state was acquired in 1853 through the Gadsden Purchase.