Coahuila y Tejas
In 1834, Mexican President Antonio López de Santa Anna shifted from a federalist political ideology to creating a centralist government and revoked the country's constitution of 1824. That constitution had established Coahuila y Tejas as a new Mexican state and had provided for each state in Mexico to create its own local-level constitution. After eliminating state-level governments, Santa Anna had in effect created a dictatorship, and he put Coahuila y Tejas under the military rule of General Martín Perfecto de Cos. When Santa Anna made Miguel Barragán temporary president, he also had Barragán install him as head of the Mexican Army of Operations. Intending to put down all rebellion in Coahuila y Tejas, he began amassing his army on November 28, 1835, soon followed by General Joaquín Ramírez y Sesma leading the Vanguard of the Advance across the Rio Grande in December.