Immigration to California: 1850-1900

When the United States took over in 1846 the population of California was made up of about  8,000 Mexican Californians and between 150,000 and 200,000 Native Americans. 

Over the next 50 years, California's population would explode and be transformed, with Americans of European descent becoming the dominant ethnic group, though communities of people from Asia and Latin America continued to exist.

The Gold Rush attracted thousands of people to California, both from other states as well as other countries. The 1850 U.S. census counted 92,597 California residents, though Native Americans were not counted. New Yorkers had become the largest immigrant group, followed by new immigrants from Mexico, migrants from several northeastern states, then Ireland, and Germany. 

The height of Gold Rush immigration came in 1852. Over 67,000 people came to California that year, with 20,000 from China. 

New immigrants caused cities to grow, especially San Francisco. In the 1850s, San Francisco became home to both communities of Irish and Yankees from the East Coast, who often fought over power in the city. Most of the Irish were working class, while business owners were often from the East Coast, though many influential business owners were also Irish. The Irish also rose to prominence in California politics, with John Downey (born in Roscommon County, Ireland) becoming governor in 1860. In the 1850s, San Francisco's Chinatown was also founded, becoming the first permanent Chinese community in North America.

As part of growing diplomatic relations between the U.S. and China, in 1868 the two countries signed the Burlingame-Seward Treaty, which granted Chinese the right to free immigration and travel within the United States. It also allowed for the protection of Chinese citizens in the United States in accordance with the most-favored-nation principle.

By 1880, the California population had passed 560,000 and immigrants from Ireland, China, New York, Germany, and England were the largest groups. 

In 1882, Congress passed the Chinese Exclusion Act, which suspended the immigration of Chinese laborers for a period of 10 years and required every Chinese person to carry a certificate identifying his or her status as a laborer, scholar, diplomat, or merchant. The 1882 Act was the first in American history to place broad restrictions on immigration.

After 1880 Italians and Portuguese began to come to California in large numbers, while Latin Americans and Asians, who had accounted for fifteen percent of the state's population in 1860, became a smaller percentage of the population. By 1900 they represented less than seven percent of Californians. Nevertheless, communities of Chinese, Japanese, Filipinos, Mexicans, and African Americans continued to survive, and many worked in agriculture or other service sectors. 

By 1890 immigrants and their descendants from midwestern states had become California's largest population group, and they would remain so into the middle of the 20th century. Immigration during the last years of the 19th century was almost entirely from Europe and Canada, and mostly from the same European regions that populated the Midwest: Germany, Britain, Ireland, and Scandinavia.