Texas seceded from the union on February 1, 1861, and on February 14, McCulloch received a colonel's commission. He was authorized to demand the surrender of all federal military posts in the state. U.S. Army General Twiggs, turned over to McCulloch all federal property in San Antonio. In return Twigg's troops were to be allowed to leave the state unharmed. On May 11, President Davis appointed McCulloch a brigadier general.