Oceanside is a coastal resort city located on California's South Coast. It is the third-largest city in San Diego County, California. The city had a population of 167,068 at the 2010 census. Together with Carlsbad and Vista, it forms a tri-city area. Oceanside is located just south of Marine Corps Base Camp Pendleton, the busiest military base in the United States. The city has experienced dramatic growth since 1970, when its population was 45,000. Much of the city's area was developed into single-family home tracts during the 1970s and 1980s. Since the 1990s, increased commercial and industrial development have diversified Oceanside's economic base.
Although the area was first settled by Native Americans, the first European explorers arrived in 1769. The Spanish missionaries under Father Junipero Serra founded Mission San Luis Rey de Francia on a former site of a Luiseño Indian village on the banks of the San Luis Rey River. In the early 19th century, the introduction of farming and grazing changed the landscape of what would become Oceanside. The area - like all of California - was under Spanish, then in 1821 under Mexican rule, and conquered by the U.S. in 1848.
In the late 1850s, Andrew Jackson Myers lived in San Joaquin County. A native of LaSalle County, Illinois, he returned in the late 1880s and lived in San Luis Rey. In 1882 Myers moved on the land that was the original town site for Oceanside. A patent for the land was issued in 1883 by the federal government. It was incorporated on July 3, 1888. The city hall as of the early 21st century stands on the former Myers homestead.