History Minute: 1835: Whites from the US immigrate into Mexico’s Texas territory and foment revolution in order to preserve slavery (016)

The Texas Revolution (October 2, 1835 – April 21, 1836) was a rebellion by Anglo-American immigrants as well as Hispanic Texans (known as Texians and Tejanos respectively) against the centralist government of Mexico in the Mexican state of Coahuila y Tejas. Although the uprising was part of a larger one, the Mexican Federalist War,[citation needed] that included other provinces opposed to the regime of President Antonio López de Santa Anna, the Mexican government believed the United States had instigated the Texas insurrection with the goal of annexation. The Mexican Congress passed the Tornel Decree, declaring that any foreigners fighting against Mexican troops "will be deemed pirates and dealt with as such, being citizens of no nation presently at war with the Republic and fighting under no recognized flag". Only the province of Texas succeeded in breaking with Mexico, establishing the Republic of Texas. It was eventually annexed by the United States about a decade later. 

The revolution began in October 1835, after a decade of political and cultural clashes between the Mexican government and the increasingly large population of Anglo-American settlers in Texas. The Mexican government had become increasingly centralized and the rights of its citizens had become increasingly curtailed, particularly regarding immigration from the United States. Mexico had officially abolished slavery in Texas in 1829, and the desire of Texians to maintain the institution of chattel slavery in Texas was also a major cause of secession,[2][3][4][5][6] although slavery is never mentioned implicitly or explicitly in the Declaration of Independence of Texas.[7] Texians and Tejanos disagreed on whether the ultimate goal was independence or a return to the Mexican Constitution of 1824. While delegates at the Consultation (provisional government) debated the war's motives, Texians and a flood of volunteers from the United States defeated the small garrisons of Mexican soldiers by mid-December 1835… 

Yellow and brown areas on the map below show the span of Mexico before Texas, New Mexico, and California became part of the US.