At the turn of the 20th century, revolution was starting to brew in the U.S.-Mexico borderlands. A group of Mexican revolutionaries had fled to the United States and were working to overthrow a dictator in their home country. They were called Los Magonistas, and both the U.S. and Mexican governments put all of their efforts to spy on them and suppress their revolution.

In this episode, historian Kelly Lytle Hernandez tells the story of this cross-border insurgency that has been left out of most U.S. history books and shares how it continues to shape border enforcement as we know it today.