Across the Rio Grande at El Paso, Texas—a city so named because it was the crossing Spaniards used to reach the country north and west of the river—sits its sister city, Ciudad Juárez. Before the Mexican-American War, the river was simply a geographical barrier within Mexico, so both sides were the same town. Today, the sister cities divided by the line are strikingly different. In Ciudad Juárez, poverty and violence have reigned; in El Paso, citizens enjoy one of the safest cities in the United States.