San Diego

San Diego (/ˌsæn diˈeɪɡoʊ/ ^ⓘ SAN dee-AY-goh; Spanish: [san ˈdjeɣo]) is a city on the Pacific coast of Southern California, adjacent to the Mexico–United States border. It is the eighth-most populous city in the U.S. and second-most populous city in California with a population of over 1.4 million, while the San Diego metropolitan area with over 3.3 million residents is the 18th-largest metropolitan area in the country. San Diego is the county seat of San Diego County. It is known for its mild Mediterranean climate, extensive beaches and parks, long association with the United States Navy, and recent emergence as a wireless, electronics, healthcare, and biotechnology development center.

Historically home to the Kumeyaay people, San Diego has been referred to as the Birthplace of California, as it was the first site visited and settled by Europeans on what is now the West Coast of the United States. In 1542, Juan Rodríguez Cabrillo claimed the area for Spain, forming the basis for the settlement of Alta California, 200 years later. The Presidio and Mission San Diego de Alcalá, founded in 1769, formed the first European settlement in what is now California. In 1821, San Diego became part of the newly declared Mexican Empire. California was ceded to the U.S. in 1848 following the Mexican–American War and was admitted as the 31st state in 1850.

The largest sectors of the economy of San Diego include military and defense-related activities, tourism, international trade, research, and manufacturing. The city is home to several universities, including UC San Diego, San Diego State University, and the University of San Diego. San Diego is the economic center of the San Diego–Tijuana region, the second-most populous transborder metropolitan area in the Western Hemisphere, home to an estimated five million people as of 2022. The primary border crossing between San Diego and Tijuana, the San Ysidro Port of Entry, is the busiest international land border crossing in the world outside of Asia (fourth-busiest overall). San Diego International Airport (SAN) is the busiest single-runway airport in the United States.

San Diego's name can be traced back to the 17th century when Spanish explorer Sebastián Vizcaíno bestowed it upon the area in 1602. He named the bay and the surrounding area "San Diego de Alcalá" in honor of Saint Didacus of Alcalá.

Prior to the Spanish establishment of San Diego, the Kumeyaay town was called Kosa'aay, meaning "drying out place" in the Kumeyaay language. After the establishment of San Diego, the Kumeyaay called town and city Tepacul Watai, meaning "Stacked Big". Luiseño speakers in the North County region called it Pushuyi.

What has been referred to as the San Dieguito complex was established in the area at least 9,000 years ago. The Kumeyaay may have culturally evolved from this complex or migrated into the area around 1000 C.E. Archaeologist Malcolm Rogers hypothesized that the early cultures of San Diego were separate from the Kumeyaay, but this claim is disputed. Rogers later reevaluated his claims, yet they were influential in shaping historical tellings of early San Diego history.

The Kumeyaay established villages scattered across the region, including the village of Kosa'aay which was the Kumeyaay village that the future settlement of San Diego would stem from in today's Old Town. The village of Kosa'aay was made up of thirty to forty families living in pyramid-shaped housing structures and was supported by a freshwater spring from the hillsides.

The first European to visit the region was explorer Juan Rodríguez Cabrillo. Sailing his flagship San Salvador from Navidad, New Spain, Cabrillo claimed the bay for the Spanish Empire in 1542, and named the site "San Miguel". In November 1602, Sebastián Vizcaíno surveyed the harbor and what are now Mission Bay and Point Loma and named the area for the Catholic Saint Didacus, a Spaniard more commonly known as San Diego de Alcalá.