After the Mexican War of Independence from Spain also, California, Nevada, Arizona, Utah, western Colorado and southwestern Wyoming became part of the Mexican territory of Alta California and most of New Mexico, western Texas, southern Colorado, southwestern Kansas, and Oklahoma panhandle were part of the territory of Santa Fe de Nuevo México. The geographical isolation and unique political history of this territory led to New Mexican Spanish differing notably from both Spanish spoken in other parts of the United States of America and Spanish spoken in the present-day United Mexican States.

When did other states become part of Mexico?