Texas County is a county located in the southern portion of the U.S. state of Missouri. As of the 2020 census, the population was 24,487. Its county seat is Houston. The county was organized in 1843 as Ashley County. Its name was changed in 1845 to Texas County, after the Republic of Texas. The 2010 U.S. Census indicates that the county was the center of population for the United States. From Wikipedia