Chapter 3, Foundations of Human Activity

The original inhabitants of the San Francisco Bay Area were about 40 cuturally diverse native tribes known as the Ohlone.  They were a society of hunter-gatherers who lived off of the land and its natural resources.


http://www.zpub.com/sf/history/sfh2.html

When the Spanish came and set up the missions, the natives were removed from their land and forced to convert to the mission system, which ended their traditional way of life.  In San Francisco, Mission Dolores was founded in 1776, and it was the 6th of 21 missions established by the Franciscans.
  www.urbantrekusa.com
In the 1820s, ships from the East Coast were coming to visit the missions along the coast of California.  They first came to barter, but more pioneers were trekking into the West.  They were accepted by the Spanish governors who allowed them to marry into some of the wealthiest  Mexican families who had large land grants.
When the Gold Rush hit Cailfornia, San Francisco was a port of entry for people who came to the area to try and find gold.  Boats of people would dock at the bay, and make their way up to Coloma, CA where gold was first discovered.  Others would take the land route from the east, trekking the unforgiving terrain and weather of the Sierras.  One such group of people we have probably learned about is the Donner Party.
In 1882, Congress passed the Chinese Exclusion Act which barred Chinese immigration.  The American sentiment was that there were too many Chinese people taking American jobs.  The Chinese that were already in the area had lived in a neighborhood that would become known as Chinatown.  Today, "San Francisco Chinatown is the largest outside of Asia as well as the oldest Chinatown in North America," (http://www.sanfranciscochinatown.com/). 
  http://www.danzfamily.com/
In San Francisco, you can also find that the neighborhoods dictate what ethnicity may be dominant in the are.  There is Japantown, North Beach (Little Italy), The Mission (Latin Americans), and Little Manila (Filipinos in Daly City, CA).