Our southwest border with Mexico is completely unlike any other part of the United States. It is also a place that needs to be personally experienced in order to fully understand the complexities and nuances of life next to another country. But Mexico is not just any country; it is our third largest trading partner, and our two nations share a cultural bond that goes back over a hundred years. This cross-border relationship hasn’t always been pretty, and at some points in history, it has been...