Rains County was one of the earlier areas of Texas to be settled. J. H. Hooker, the first known settler, built a grist mill on the Sabine River here in the 1840s. Emigrants from the Old South arrived after 1840, although the county was not created until 1870. Its name honors pioneer Emory Rains (1800-1878), who served as senator in the 8th Legislature from the district out of which this county was later carved and had a long public service career. Rains County is also known as the birthplace of the Farmers Cooperative and Educational Union of America, founded in 1904.