We are all familiar with the tales of the Underground Railroad, how enslaved people in the South risked life and limb to escape to the Northern States before and during the Civil War. Some of us may be surprised to learn that there was an Underground Railroad network in Texas. Maria Hammack, whose research on this subject is coming to light in a doctoral thesis at the University of Texas in Austin, estimates that before the Civil War between 5,000 to 10,000 slaves escaped to Mexico to obtai ...