Henderson County is a county located in the U.S. state of Texas. As of the 2010 census, its population was 78,532. The county seat is Athens. The county is named in honor of James Pinckney Henderson, the first Attorney General of the Republic of Texas, and later Secretary of State for the republic.Henderson County was established in 1846, the year after Texas statehood. Its first town was Buffalo, laid out in 1947.