When Mexico achieved its independence from the Kingdom of Spain and its Spanish Empire in 1821, what is now Arizona became part of its Territory of Nueva California, ("New California"), also known as Alta California ("Upper California").Timothy Anna et al., Historia de México. Barcelona: Critica, 2001, p. 10. Descendants of ethnic Spanish and mestizo settlers from the colonial years still lived in the area at the time of the arrival of later European-American migrants from the United States.
