Tijuana is itself a creation of the border. The borderline was drawn here in 1848, as the United States completed its conquest of the present-day American Southwest. The border, along with the growth of San Diego and Los Angeles, gave Tijuana a reason to be.
It's hard enough to drive through the Arizona desert, where the sun is harsh and the distances immense. This is the story of people who walk it.
In particular, it's the story of Brenda, who asked us to use only her first name. She told us yet another of the unbelievable stories you hear in the Borderland.
We met her in Nogales, Sonora, on the northern border of Mexico opposite Arizona. She was living in a shelter for deported people, where she told us of her brief and difficult stay in the United States.
Columbus, N.M., is all about the border. It's an official border crossing. Its history centers on a cross-border raid. In more recent years, it was a transit point for illegal weapons heading south into Mexico.
It's also the destination for children heading north to a U.S. school.
All the different strands of Columbus came together when we spent the day with the new mayor of the village. Phillip Skinner, former real estate developer and maquiladora owner-turned politician and school bus driver, was inaugurated early this month, on the morning we rolled into town.
We had just finished our time in Juarez, Mexico, when we had dinner with some distant relations on the U.S. side of the border. "You," one of my relatives said, "are the first Juarez survivors we've seen in some time."