After Mexico achieved independence from Spain, Seguín was named the sole representative from Texas to the constitutional convention.
Seguín assisted Stephen F. Austin in choosing land for the first colony of American settlers to immigrate to Texas.
[1] His paternal grandfather, Bartolomé Seguin, had moved to Spanish Texas from the Mexican interior soon after the founding of the town in 1718.
[1] Seguin married María Josefa Becerra, daughter of a non-commissioned officer from Presidio La Bahía (Goliad, Texas), stationed at Bexar.
[3] After 1824, he added a 9,000 acres (3,600 ha) ranch located on present-day River Bend Golf Club near Floresville.
His arbitrary rule caused much dissatisfaction within Texas, and Seguin helped to organize the counterrevolt that deposed de las Casas.
A governing council was created to help lead the province until Spanish troops could regain control; Seguin held one of the seats.
While he was en route, the Spanish army, under José Joaquín de Arredondo, had defeated the invaders, killing 1300 Texians at the Battle of Medina, and resumed control of the province.
In 1822, he was fully restored as postmaster and in 1825 he was appointed quartermaster of Presidio San Antonio de Bexar, a position he held for a decade.
For the first time, people would be allowed to settle in Texas from other countries, including the neighboring United States.
In 1821, the governor of Spanish Texas, Antonio María Martínez, asked Seguin to act as ambassador to Moses Austin and inform him that he had been awarded the first colonization contract.
[1] Several months later, Seguin and Juan Martín de Veramendi met Austin's son, Stephen at Natchitoches and escorted him into Texas.
Three weeks into their trip, several of Seguin's employees found them to deliver the news that Mexico had been granted its independence from Spain.
[9] The new Mexican constitution was similar to that of the United States, with the major exception that it established Catholicism as the national religion.
In an extension of the Spanish policy of 1821, the colonization law would allow state governments to grant land to empresarios, who could then allot it to individual colonists.
Austin went directly to San Antonio de Béxar to meet with Seguin after the Convention of 1833 adjourned on April 14.
[15] During the revolution, Seguin supplied the Texian army with beef, cattle, horses, and corn, as well as rockets for the storming of Bexar.