Mexico requires parents to register their children when they're born in order to get a birth certificate. It's not done automatically, like it typically is in the United States. But many of Mexico's poorest people don't bother, which can leave those children disadvantaged for life.
Millions of undocumented immigrants live in the United States. Many came from Mexico but there are many undocumented Mexicans living in their own country as well. One man is helping Mexico's undocumented people attain their civic rights and dignity.