The state of Texas, home to one of the largest prison systems in the country, opened its first penitentiary in 1849. The Walls Unit in Huntsville was the genesis of a prison system that became the home of notorious convicts and the focus of much debate about incarceration and the death penalty in the United States. The Walls Unit housed gunslinger John Wesley Hardin, members of the Clyde Barrow and Bonnie Parker gang, and infamous drug cartel leader Fred Carrasco. Built using convict labor, the Walls Unit was heralded as a modern approach to incarceration in Texas. The prison dominated the landscape of the town of Huntsville when it was built and remains central to that community today.