Founded as a mission in 1749, San Diego’s first transportation and production networks of California and the Southwest in the nineteenth growth came with its conflictive integration into century. Since the Second World War, Sunbelt metropolitan growth has boomed not only along the Bay, but also in northern, coastal and inland suburbs (La Jolla, Escondido, Imperial Beach) stretching south along highways towards Mexico. By 1990 San Diego became the sixth-largest city in the US (2000 estimates 1,208,998). Its Mediterranean climate and ambiance and attractions like the zoo and Sea World Aquarium bring in tourists, while military facilities and service-sector development have sustained economic growth. The University of California, San Diego and baseball’s Padres enrich the metropolitan area.

Tijuana, a contiguous Mexican boom-city has provided labor, consumers, leisure and “vice” for the US, especially since the 1920s. US—Mexico border issues today focus on industrial development, environment and immigration. While Tijuana remains famous for gambling and alcohol, illegal/cheap pharmaceuticals are big business and coastal resorts are growing. As in other border areas, the dialectic of development shapes both cities.