is a county located in the southern portion of the U.S. state of Missouri. As of the 2010 census, the population was 26,008. Its county seat is Houston. The county was organized in 1843 as Ashley County, changing its name in 1845 to Texas, after the Republic of Texas.
Texas County was originally created in 1843 and named for William H. Ashley, the first lieutenant governor of Missouri. It was later organized on February 14, 1845, when it was also renamed for the Republic of Texas.
A seat of justice for the county was laid out in 1846 near the center of the county on Brushy Creek and named Houston for the first president of the Texas Republic. The historic Texas County Courthouse, built in 1932, was the county's sixth and now serves as the county administrative center. It was remodeled in 1977 and again in 2007. A new justice center was completed in 2008.
Rugged hills, springs, creeks, rivers and caves abound in Texas County. There have been many Native American mounds found in the county. Their paintings remain upon various bluffs over ancient campsites. The area was part of the 1808 Osage Native American land cession.
Pioneers came to Texas County in the 1820s from Virginia, Kentucky, Tennessee and the Carolinas and set up sawmills along the Big Piney River. Pioneers made a nice income rafting the timber down the Piney River toward St. Louis. Some 48,000 acres (190 km2) in the north and northwest part of the county is now part of the Mark Twain National Forest. Several acres in the southeast part of the county are part of the Ozark National Scenic Riverways Park. Small family farms are still a major part of the landscape of the county. The population of the first Federal Census of Texas County in 1850 was 2,312 citizens.
The American Civil War period was a time of turmoil in Texas County. The populace was predominantly Southern. The courthouse was occupied during the war by the Union Army as headquarters. Houston was an important point on the route from federal headquarters in Springfield to headquarters in Rolla. Some skirmishes were fought here. Confederate soldiers stormed the town, burning every building.
On February 26, 2015, a gunman shot and killed seven people in several locations across the town of Tyrone. The suspect was later found dead of a self-inflicted gunshot wound. It was the worst mass murder in Texas County's history. Prior to the mass shooting, the county had an average of one homicide per year.