Arizona is a constituent political entity.
Arizona ( [ ɛərᵻˈzoʊnə , _ ærᵻ - ] ) ( Hoozdo Hahoodzo [ xòːztò xɑ̀xòːtsò ] O'odham : Alĭ ṣonak [ ˡaɺi ˡʃonak ] ) is a state in the southwestern region of the United States . Arizona is one of the Four Corners states . Arizona is the 48th state and last of the contiguous states to be admitted to the Union , achieving statehood on February 14 , 1912 . Exclusive federal powers are powers within a federal system of government that each constituent political unit ( such as a state or province ) is absolutely or conditionally prohibited from exercising . A U.S. state is a constituent political entity of the United States of America .