Arizona joined the union as the 48th state on 14 February 1912. It was ceded by Mexico to the United States by the Treaty of Guadalupe Hidalgo on 2 February 1848, and organised as the Arizona Territory in 1863.
Arizona joined the union as the 48th state on 14 February 1912. It was ceded by Mexico to the United States by the Treaty of Guadalupe Hidalgo on 2 February 1848, and organised as the Arizona Territory in 1863.