First known Eastland area inhabitant was Frank Sanchez (d. 1867), who grazed herds here in the 1850s. The United States in 1853 established Army posts at Fort Phantom Hill, in present Taylor County, and Fort Belknap, in present Young County, giving the frontier protection against hostile Indians. This opened a modest influx of settlers, including families named Bell, Birden, Birt, Blair, Ellison, Fitzwaters, Flannagan, Gilbert, Herring, Highsaw, McGough, Mansker, Melburn, Oliver, Owens, Richards, Shirley, Singleton, Upton, and Wyatt, from "old states" of Alabama, Arkansas, Georgia, Kentucky, Mississippi, North and South Carolina, and Tennessee. The county was created, but not organized, in 1858. The U.S. Census for 1860 showed 99 residents. When Texas seceded from the Union in 1861, and Army garrisons withdrew, many pioneers left or took refuge at Blair's Fort, in southeastern part of the county.
Post-Civil War settlers included such leaders as Dr. Edwin Daniel Townsend, who arrived from Kentucky in 1871. The county was organized in an election held Dec. 2, 1873, with Merriman designated county seat (in violation of legislation creating the county). In 1875 the government was moved to Eastland, founded that year by investor Charles U. Connellee (1851-1930).