Originally published in 1994, Tijuana: The History of Mexican Metropolis was the first book-length study of Tijuana to have appeared in decades. Thurber Proffitt produced an in-depth history that theorizes a symbiotic frontier—one that is mutually advantageous, but also, interdependent, so much so that San Diego, California, and Tijuana, Baja California, emerge as a fused metropolis, a Latinx megalopolis.