The city of San Francisco is technically in San Francisco County, but the city and county of San Francisco are the same entity. San Francisco is the only consolidated city/county unit in the state of California.
San Francisco was founded on June 29, 1776, and named after St. Francis of Assisi. In 1849, gold was discovered in northern California, beginning the Gold Rush and bringing in around 50,000 people to San Francisco in less than a year. Even once the Gold Rush was over, and in spite of being close to the San Andreas and Hayward Faults that cause frequent earthquakes, the city continued to grow. As of 2013, San Francisco had a population of 837,442 people.