King Bryan was born in January 1818, in Berwick, Louisiana. He moved to Liberty County, Texas, sometime before 1840, and he married Amanda Whitlock there. Bryan worked as a farmer, and by 1860, he owned $8,000 of real estate and $5,000 of personal property. He also owned at least 3 enslaved laborers. Bryan served in the Texas state legislature from November 1859 until November 1861, and sat on the apportionment committee, the private land claims committee, and the stock raising committee.
Bryan received a commission as captain of Company F of the 5th Texas Infantry in 1861. He was promoted to lieutenant colonel in November 1862. He was wounded in the Battle of Gettysburg and again in the Battle of the Wilderness. He obtained a leave of absence in August 1864 and spent the next several months in Richmond. He returned to Texas after the war, but he never fully recovered from his wounds. He died in Beaumont, Texas, on October 8, 1866.