In the Rio Grande Valley, what started as a couple fighting for their love turned into a system that helped others.

A documentary film depicts two mixed-race families — the Webers and the Jacksons — that settled in the Rio Grande Valley.

John Weber purchased Sylvia Hector’s freedom from a neighbor after their third child.

The couples bought thousands of acres of land by the Rio Grande — located in Pharr, San Juan, Alamo and Donna. It served as an excellent escape route for slaves fleeing to Mexico.

Watch the video above for the full report.