Mexican War of Independence
Although Mexico gained its independence in September 1821, the marking of this historical event did not take hold immediately. The choice of date to celebrate was problematic, because Iturbide, who achieved independence from Spain, was rapidly created Emperor of Mexico. His short-lived reign from 1821–22 ended when he was forced by the military to abdicate. This was a rocky start for the new nation, which made celebrating independence on the anniversary of Iturbide's Army of the Three Guarantees marching into Mexico City in triumph a less than perfect day for those who had opposed him. Celebrations of independence during his reign were marked on September 27. Following his ouster, there were calls to commemorate Mexican independence along the lines that the United States celebrated in grand style its Independence Day on July 4. The creation of a committee of powerful men to mark independence celebrations, the "Junta Patriótica", organized celebrations of both September 16, to commemorate Hidalgo's grito and the start of the independence insurgency, and September 27, to celebrate actual political independence.
Presidio San Agustín del Tucsón
When Mexico achieved its independence from Spain in 1821, the Tucson Presidio still had a Spanish garrison that accepted Mexican freedom, likely because the Spanish aristocracy's hold on northern Sonora wasn't broken as result of the war. The aristocracy supported the independence of their country which fueled the rebellion, many also led the armies that won the war. Since 1775 and even longer due to the Pima villages, Tucson has always been inhabited, unlike several other Spanish settlements in the area. During the Mexican period at least seventy-five percent of Tucson was populated by Native Americans. After independence Mexico slipped into a depression and frontier colonization quickly became under-supplied with both men and food, old alliances between Spain and the natives ended. Other tribes continued to be peaceful, the Pimas remained friendly along with Yaquis and a few other groups in southern Arizona. Apaches remained a serious threat and most of the Spanish frontier settlements in Arizona and New Mexico were abandoned and the populations fled south. Generally the Mexicans remained only in the coastal states of Texas and California, creating more Indian country in between Mexico City and California. Landlocked settlements in what is now northern New Mexico survived with Tucson and a few other mission towns such as the San Xavier and the Tumacacori Mission. Apaches continued raiding and skirmished with Mexicans just outside the Presidio several times, they raided the livestock just like they did the Spanish herds. The Mexicans were less able to defend themselves due to the depression.