San Francisco harbor in 1850 or 1851. During this time, the harbor would become so crowded that ships often had to wait days before unloading their passengers and goods.
The population boom included many workers from China who came to work in the gold mines and later on the Transcontinental Railroad. The Chinatown district of the city became and is still one of the largest in the country; the city as a whole is roughly one-fifth Chinese, one of the largest concentrations outside of China. Many businesses founded to service the growing population exist today, notably Levi Strauss & Co. clothing, Ghirardelli chocolate, and Wells Fargo bank. Many famous railroad, banking, and mining tycoons or "robber barons" such as Charles Crocker, Mark Hopkins, Collis P. Huntington, and Leland Stanford settled in the city in its Nob Hill neighborhood. The sites of their mansions are now famous and expensive San Francisco hotels (Mark Hopkins Hotel and the Huntington Hotel).
As in many mining towns, the social climate in early San Francisco was chaotic. Committees of Vigilance were formed in 1851, and again in 1856, in response to crime and government corruption, but also had a strong element of anti-immigrant violence, and arguably created more lawlessness than they eliminated.[dubious - discuss] This popular militia movement lynched 12 people, kidnapped hundreds of Irishmen and government militia members, and forced several elected officials to resign. The Committee of Vigilance relinquished power both times after it decided the city had been "cleaned up." This mob activity later focused on Chinese immigrants, creating many race riots. These riots culminated in the creation of the Chinese Exclusion Act in 1882 that aimed to reduce Chinese immigration to the United States by limiting immigration to males and reducing numbers of immigrants allowed in the city.[dubious - discuss] The law was not repealed until 1943.
Market Street, early 20th century
The City of San Francisco was the county seat of the County of San Francisco from 1849 to 1856. Until 1856, the city limits extended west to Divisadero Street and Castro Street and south to 20th Street. In response to the lawlessness and vigilantism that escalated rapidly between 1855 and 1856, the State of California decided to divide the County; and carved out the city core from the rest of San Francisco County. A straight line was drawn across the tip of the San Francisco Peninsula just north of San Bruno Mountain. Everything south of the line became the new County of San Mateo, while everything north of the line became part of the new consolidated City-County of San Francisco - California's first and, to date, only consolidated city-county.
In autumn of 1855, a ship bearing refugees from an ongoing cholera epidemic in the Far East (authorities disagree as to whether this was the S.S. Sam or the S.S. Carolina but primary documents indicate that the Caroline was involved in the epidemic of 1850 and the SS Uncle Sam in the epidemic of 1855) docked in San Francisco. As the city's rapid Gold Rush area population growth had significantly outstripped the development of infrastructure, including sanitation, a serious cholera epidemic quickly broke out. The responsibility for caring for the indigent sick had previously rested on the state, but faced with the San Francisco cholera epidemic, the state legislature devolved this responsibility to the counties, setting the precedent for California's system of county hospitals for the poor still in effect today. The Sisters of Mercy were contracted to run San Francisco's first county hospital, the State Marine and County Hospital, due to their efficiency in handling the cholera epidemic of 1855. By 1857, the order opened St. Mary's Hospital on Stockton Street, the first Catholic hospital west of the Rocky Mountains. In 1905, The Sisters of Mercy purchased a lot at Fulton and Stanyan Streets, the current location of St. Mary's Medical Center, the oldest continually operating hospital in San Francisco.