Clarksville is a city in Red River County, Texas, in the United States in the northernmost part of the Piney Woods region of East Texas. As of the 2000 census, the city population was 3,883. It is the county seat of Red River County.
An early trapper and settler, Henry Stout, who had been living at Pecan Point and then at Jonesborough since 1819, patented the land near the springs on Delaware Creek, a hundred yards from the present courthouse square, in March 1838. He received "a league and a labor" -- almost 3,700 acres -- which he almost immediately conveyed to Mrs. Isabella H. Clark, husband of James Clark, after whom the town was named and who was instrumental in its early development and in making it the seat of Red River County.
Clarksville was chartered as a town by the Republic of Texas in 1840, with a population of 600. By 1870, the population had reached 1,000, which made it officially a "city." The population in 1890 was just under 1,600 and reached its peak of 4,350 in 1950. The population has not changed significantly since then.