Set around a graceful, curving bay, San Diego is now the second most-populous city in California. The city's history - like that of many Californian places - can be traced back to when Spanish missionaries first came to the area. In San Diego, the missionaries pre-dated those in the rest of the state by a considerable time; the first known Christian service took place in November 1602. The first regular, consistent mission was established in 1769, and soon it boasted the largest population in all of Spain's American territories.
After passing into Mexican possession in 1821, San Diego became part of the United States in 1848. The settlement was granted city status two years later in recognition of its growing size and importance. With the arrival of the Santa Fe Railroad in the 1880s, San Diego really took off as an important transport hub, and began to develop rapidly. Its importance became such that during the Second World War, the US Navy made San Diego its Pacific Command Centre.