"Today, as Black History Month comes to a close, we want to explore a chapter of U.S. history that is often overlooked. It's about the escape of enslaved people from the American South to Mexico.
Now, most of us are familiar with the Underground Railroad, the network of people who helped those fleeing slavery to escape north. Harriet Tubman played a key role in that effort, of course. And today, the federal government is once again making plans to put her portrait on the front of the $20 bill. But there was also a southbound route to freedom. Thousands of enslaved people fled plantations to make their way to the Rio Grande, which was for them a river of deliverance. NPR's John Burnett has our story."