In the late 1840's, after Texas became a state, the US Army would come to San Antonio, making the city the headquarters for the Department of Texas and quartermaster supply depot for all its 17 outlying forts.
In January of 1861, a special session would adopt a resolution which validated and approved the calling of the Secession Convention. On January 28, the Secession Convention assembled and four days later, it had passed by a vote of 168 to 7, an Ordinance of Secession, which provided for the final seperation of Texas from the Union.
The Committee of Public Safety felt they had to move quickly before the Federals had time to destroy their forts and remove the military arms and equipment which Texas would need to protect its frontier and so appointed a committee of four men to go to General Twiggs in San Antonio and demand the surrender of al Federal property under his control. The Committee of Public Safety also appointed Ben Mc Culloch a colonel of Cavalry and Charged him with raising a force of militia in casse force was needed to persuade Twiggs into surrendering the Federal property.
Two days after the surrender of the Federal forces, Twiggs issued General Order Number 5, on February 18th, which delivered possession of all military posts and property within the state to the Commissioners. A month later, Texas would join the Confederacy.