SAN DIEGO Urban Fabrics City Map: PRINTSAN DIEGO California. Home of the Tipai Ipai indigenous people, the geographic site of San Diego was "claimed" for Spain in 1542 and was ceded to the United States after the Mexican American War in 1842. Town building throughout the late nineteenth century accelerated with the arrival of the railroad. In the twentieth century, the city became a hub for aeronautics, military and defense. Tourism is high, thanks to a sunny climate, beaches to the west