Reagan County was formed from Tom Green County, created on March 7, 1903, and organized on April 20, 1903. It was named in honor of John H. Reagan, 1818-1905, an Indian fighter and surveyor, member of the Texas Legislature and United States Congress, and postmaster general of the southern Confederacy. The county seat was Stiles from 1903 to 1925 and has been Big Lake since.