San Diego, the second-largest city in California. San Diego is located on San Diego Bay in the southwest part of the state.
Juan Rodríguez Cabrillo a Portuguese navigator claimed the bay for Spain in 1542. The site was named San Miguel by Cabrillo. He renamed the place San Diego after the 15th-century saint.
Franciscan father Junípero Serra established the first California mission there—San Diego del Alcala in 1769. Mexico won control of the town after declaring its independence from Spain. In 1846, during the Mexican War, San Diego was seized by the U.S.. After California joined the Union it was incorporated as a city in 1850,
San Diego's excellent natural harbor is a busy commercial port and a hub of U.S. naval operations. The naval training center at San Diegowas stopped due to defense cutbacks.Major other industries include electronics, aerospace and missiles, medicine ,scientific research, oceanography, and agriculture. Its excellent climatic condition and proximity to Mexico have made San Diego tourist friendly and contributed to the city's economy.