There are 5 US Post Offices in Clay County serving a total of 7,464 residents equating to 1,493 residents per post office. It's estimated that approximately 11,913 packages are handled across the 5 county post offices annually. Clay County is a county located in the U.S. state of Texas. As of the 2010 census, its population was 10,752. The county seat is Henrietta. The county was founded in 1857 and later organized in 1860. It is named in honor of Henry Clay, famous American statesman, Kentucky Senator and United States Secretary of State. Clay County is part of the Wichita Falls, Metropolitan Statistical Area in North Texas. Several railroads once served Clay County, including the Wichita Falls Railway, one of the properties of Joseph A. Kemp and his brother-in-law Frank Kell, along with twenty-nine other stockholders. The Wichita Falls Railway linked Henrietta with Wichita Falls. Built in 1894-1895, it was sold in 1911 to the Missouri-Kansas-Texas Railroad, also known as the Katy. The original eighteen miles of track was abandoned in 1970. The Wichita Falls rancher, oilman, and philanthropist Joseph Sterling Bridwell owned a ranch in Clay County, among his multiple holdings. Clay County is represented in the Texas House of Representatives by the Republican James Frank, a businessman from Wichita Falls."