Arizona states of Sonora and Baja California. Arizona is the 48th state and last of the contiguous states to be admitted to the Union, achieving statehood on February 14, 1912, coinciding with Valentine's Day. Historically part of the territory of "Alta California" in New Spain, it became part of independent Mexico in 1821. After being defeated in the Mexican–American War, Mexico ceded much of this territory to the United States in 1848. The southernmost portion of the state was acquired in 1853 through the Gadsden Purchase. Southern Arizona is known for its desert climate, with very hot summers and mild winters.
Admission to the Union enabling act was a common historic practice, a number of states were admitted to the Union without one. In many instances, an enabling act would detail the mechanism by which the territory would be admitted as a state following ratification of their constitution and election of state officers. Although the use of such an act is a traditional historic practice, a number of territories have drafted constitutions for submission to Congress absent an enabling act and were subsequently admitted. The broad outline for this process was established by the Land Ordinance of 1784 and the 1787 Northwest Ordinance, both of