Mexico ends more than 300 years of rule under Spanish colonialism with the signing of the Treaty of Cordoba. The revolution started on September 16, 1810 and did not end until 1821, when the Spanish yoke was finally cast off. Mexicans (in Mexico) celebrate their independence day on September 16th, the day the revolution against Spain started, and not the "Cinco de Mayo" celebration we have here in the U.S.

This also ended Spanish rule in the U.S. and its territories in the west and southwest. With the
exception of Texas, under which some colonialism under Stephen F. Austin was allowed, all other territory was under Mexican rule. Mexico undid the influence of the Spanish Missions and allowed land ownership to government favorites under the generous land grants of the era. Vast ranchos were established under the leadership of the grantees. Even non-Mexicans were allowed to own land if they swore allegiance to Mexico and converted to Catholicism. An excellent example of this was Robert Livermore who was given the Rancho Las Positas grant, which made him a contemporary of Bernal, Sunol, Vallejo, Estudillo, Alvarado, Alviso, Pacheco, Peralta and others.

The Mexican government did not fully recognize the importance and wealth of California, and the inhabitants (the Californios) were treated as second class Mexican citizens.