The Underground Railroad ferried enslaved people to the North, but turning south to Mexico provided opportunity for freedom, too. Alice L. Baumgartner is assistant professor of history at the University of Southern California, and she joins guest host John McCaa to discuss her research into the thousands who made their way south of the border, where slavery was outlawed, and where the formerly enslaved could hope to find independence and agency. Her book is called “Runaway Slaves to Mexico and the Road to the Civil War.”