A part of the Miller and Fisher Grant in 1842. Created a county March 13, 1874. Organized January 5, 1875. Named in honor of General Thomas Green, 1814-1864. A veteran of San Jacinto. Member of the Somervell Expedition. A Confederate officer. First mail routes to the Pacific converged here in 1858. County seat, Ben Ficklin, 1875. San Angelo, since 1882