The city of Cooper /ˈkʊpər/ is the county seat of Delta County, in the U.S. state of Texas. Located between the north and south forks of the Sulphur River, Cooper is the largest settlement within Delta County. As of the U.S. Census of 2010, Cooper had a population of 1,969.First inhabited by native people, Cooper was founded around 1870, at the same time that Delta County was established. Cooper grew rapidly and it quickly became the center of local events.