California’s History of Immigration: How Immigrants Built the State, and How They Were Treated in Return

California, the most populous state in the union, with slightly more than 39.6 million residents, also has the largest population of immigrants. As of 2019, the most recent year with a precise count available, 10,564,220 Californians were born outside the United States—27 percent of the state’s population.

In the U.S. as a whole, 13.7 percent of the population is made up of immigrants—about half of California’s percentage. Most of the migrant population is composed of folks properly documented to reside in the U.S.. According to the Migration Policy Institute (MPI), about 2.7 million undocumented immigrants live in California.

Where do those undocumented immigrants come from? Mostly Mexico, Central and South America—79 percent were born in those regions, the largest portion (61 percent) from Mexico, per MPI data. Asian immigrants come in second, at 18 percent of the undocumented population.

Those born in Latin America also make up the largest percentage of legally authorized immigrants, at 49.5 percent. Asia-born immigrants are next at 40.2 percent, with Europeans comprising 6.2 percent of all immigrants now living in California.

California is a state built by people who came from somewhere else. It was not until 2010 that people born in California outnumbered those who had migrated from either another state or another country. Today, about 56 percent of Californians are “native” to the state. But if you go back to its founding, the entire territory and everyone in it switched countries and became “immigrants” of sorts overnight.

1848: California’s Residents Become Instant Americans

By early 1848, nearly two solid years of war against Mexico had cost 13,000 American lives. At that time, the entire U.S. population was about 17 million. In today’s terms, the Mexican-American War would have left 254,000 Americans dead. But Mexico was hurt even worse, with 25,000 casualties.

The war started with a bitter dispute over Texas. The region had declared independence from Mexico in 1836, but the American government in Washington, D.C., dragged its feet on making Texas officially part of the U.S. When U.S. President James Polk decided it was time to annex Texas, war broke out on April 25, 1846.

By Feb. 2, 1848, the Americans had pushed far south and captured Mexico City. The war ended with the signing of the Treaty of Guadalupe Hidalgo on that day. Under the treaty, Mexico not only conceded any rights to Texas, it agreed to sell 525,000 square miles of other territory to the U.S. for the sum of $15 million (approximately $550 million in 2022 money). Among that huge swath of land, the territory that two years later became the state of California.

The treaty also gave the Mexicans living in California the choice to become U.S. citizens. In effect, these citizens of a “foreign” country, including an elite of wealthy landowners—the territorial Governor Pío Pico among that group—became instant immigrants. The treaty also promised that their land rights would be honored. Fast-moving events, however, would render that promise mostly hollow. Just about a week before the treaty ending the war was signed, a momentous event took place that would, almost overnight, turn California into a land of dreams for immigrants and migrants from all over the U.S. and the world—and something of a nightmare for Californians.

At Sutter Creek in the Sierra Nevada, at a mill owned by “Captain” John Sutter, a Swiss-German explorer who built the first white settlement in California, a man named James Marshall discovered gold. Over the next two years, more than 300,000 migrants flooded California, with dreams of striking it rich. 

Mexicans, who until 1821 (when Mexico declared its independence) were Spanish subjects, formed the largest bloc of immigrants to early California. Independence from Spain provided a great incentive for Mexicans to move north in search of land and wealth. Under Spanish rule, all lands were held by the crown and land grants were few. That changed when the new government of Mexico took over. Starting in 1834, the government issued more than 600 land grants to well-to-do Mexican immigrants as well as to white settlers such as Sutter. 

Next Wave of Immigrants Arrives From China

It was a century-and-a-half before social media, but news of the discovery on Sutter’s land spread in a hurry, not only across the U.S. and its territories, but around the world. In 1849, word of the gold strike reached Hong Kong and quickly disseminated throughout China—a country then in the midst of a 30-year economic depression.

The struggling Chinese people envisioned a better life in this land they called gam saan, or “gold mountain.” By 1851, an estimated 25,000 had left their homes and arrived in California, instantly becoming about 10 percent of the state’s entire population at the time. But as happened with most aspiring Gold Rush millionaires, very few of the Chinese immigrants found success in the mining business.

The state was hardly welcoming to the Chinese immigrant miners. In 1850 the newly formed state legislature passed a “foreign miner’s tax” that charged any gold prospector who was not a U.S. citizen $20 per month—the equivalent of almost $750 today—just to hold a license. Though in theory the tax applied to all immigrant miners, in practice it was collected only from the Chinese and Mexican immigrants who followed their dreams to California. White European immigrants generally got off without paying.

The tax expired in 1870, but by that time the state had drained Chinese miners of $5 million (more than $100 million in 2022 cash). Between the tax and general brutality of trying to make it in the mining business, thousands of Chinese immigrants simply gave up. Being broke, they couldn’t afford passage back across the Pacific. So they took whatever work was available—which thanks to pervasive discrimination, wasn’t much.

One industry was happy to hire Chinese labor—the railroads. As many as 20,000 Chinese laborers laid tracks for the Transcontinental Railroad ,taking pay between 30 and 50 percent less than their white counterparts, and dying at a frightening rate from the hazardous nature of their work. While the exact number of Chinese workers killed remains uncertain, historians estimate the figure could be over 1,000.

When railroad work dried up, Chinese immigrants continued to face discrimination that shut them out of most jobs available to white Californians of that era. So many opened their own businesses—shops, laundries, restaurants and whatever they could as they attempted to survive in the “gold mountain.”

The Chinese Exclusion Act

The Chinese received little thanks for their labor, and the services they provided in constructing the foundations of California’s infrastructure. In 1882, driven mainly by California legislators and politicians, the U.S. Congress passed the Chinese Exclusion Act, a law designed specifically to restrict immigrants from Asia from entering the country. 

In 1910, with San Francisco a primary port of entry for Chinese immigrants, the Bureau of Immigration quickly constructed a facility on Angel Island, about six miles offshore in San Francisco Bay. Despite its nickname of “the Ellis Island of the West,” the purpose of the facility was less to welcome immigrants, than to keep them out.

The Chinese Exclusion Act not only created a nightmare for immigrants from China—many of whom forged identities to pass themselves off as merchants, clergy, diplomats or teachers, groups that were exempted from the Act—it served as the model for decades of restrictive immigration laws. Most notoriously, the Immigration Act of 1924 set strict quotas on immigrants of specific races and nationalities, and banned immigrants from Asia altogether.

The 1882 Exclusion Act was finally repealed in 1943, but the new law placed a limit on visas for Chinese immigrants at 105 per year nationwide. About 13,000 Chinese Americans served in World War II, but about half had still been denied citizenship due to the Exclusion Act. A new immigration law passed in 1952, however, repealed the last vestiges of “exclusion” while maintaining strict quotas on Chinese immigration. The quota system was not swept away until the Immigration and Naturalization Act of 1965, and as a result over the following decade, the Chinese American population doubled.

California Immigration in the 20th Century

Immigration from Mexico into California exploded in the early 20th century. From the turn of that century to 1920, the Mexican American population in the state ballooned by a factor of 11, from just over 8,000 in 1900 to more than 88,000 two decades later. That made Mexican Amercans about 3 percent of the state’s population at that time. Today, Mexican Americans comprise about 26 percent of California’s population, and they make up 84 percent of the state’s Latin American residents. 

Most immigrants from Mexico, however, did not make the trip to California directly from south of the border. They most often crossed the border into Texas and remained there for a few years before migrating west to California with the hope of better-paying jobs. In the first third of the 20th century, Mexican immigrants tended not to settle in neighborhoods exclusively populated by other Mexicans, but in communities with diverse immigrant populations.

Prior to 1930, many Mexicans in Los Angeles—the most popular city for Mexican immigrants—settled in an area called the Plaza which today also includes the city’s Little Tokyo and Chinatown neighborhoods, and in that era also housed a large population of Italians. 

In 1929, however, came the stock market crash which ignited the Great Depression. As millions of people lost their jobs, Mexican immigrants came to be seen as unwelcome competitors with white Americans for the increasingly scarce  jobs that remained. Pres. Herbert Hoover announced a program he called “Real Jobs for Real Americans.” 

In reality, the program was essentially what today might be called “ethnic cleansing.” In California and other states with large Mexican immigrant populations, local governments staged “repatriation drives,” which were actually mass, forced deportations. According to research by former California state Senator Joseph Dunn, 1.8 million U.S. residents were forcibly deported to Mexico during the 1930s—and 60 percent of them, almost 1.1 million, were U.S. citizens who despite their citizenship were not considered “real Americans” either by the government or large segments of the white population.

Under Hoover, laws were put in place banning the hiring of anyone of Mexican descent into a government job, and large corporations including California’s powerful Southern Pacific Railroad got on board with the program, laying off thousands of Mexican American workers.

War Brings Mexican Workers Back to California

World War II brought a sudden change, if not in racial and ethnic bigotry, than at least in attitudes toward Mexican workers. Established by executive order by Pres. Franklin D. Roosevelt in 1942, the Mexican Farm Labor Program, better known as the Bracero Program, allowed Mexican laborers to enter the United States on short-term work contracts, primarily to fill a shortage of agricultural workers created by the military draft.

The program remained in place for 22 years, bringing about 4.6 million laborers from Mexico into the U.S., most of them into California. While the program created opportunities for Mexican immigrants to legally enter the country, American employers too often looked to skirt the program’s requirements, hiring undocumemted workers instead of those who arrived through the Bracero Program. 

The influx of undocumented workers created a backlash and in 1954, under Pres. Dwight D. Eisenhower, the U.S. government instituted the rather shockingly named (by today’s standards) “Operation Wetback.” It was yet another program of mass deportation that sent about 1.1. million workers back to Mexico.

California Immigration Today

The COVID-19 pandemic and Donald Trump-era anti-immigration policies have slowed the pace of immigration to California. According to research performed at the University of California-Merced, the state’s immigrant population, including documented and undocuemented immigrants as well as those who have won U.S. citizenship, dropped by six percent from 2019 to the end of 2020. That means the figure of 10,564,220 immigrant residents cited at the top of this article fell to about 9.7 million in approximately 12 months.

Other factors slowing immigration from Mexico, according to a New York Times report, include improved economic conditions in Mexico, the aging of Mexico’s own population, and the collapse of the U.S. housing bubble in the mid-2000s, which reduced demand for laborers to work on home construction and maintenance.

In June of 2022, however, Gov. Gavin Newsom declared “Immigrant Heritage Month,” a signal that California has at least tried to change its attitude toward its immigrant population from the days of mass deportations and bans on entry of the previous century.

“Immigrants, whether they arrived to seek safety or opportunity, have been integral to the identity and growth of California as we know it,” Newsom wrote in his proclamation. “The state will continue to support and stand with immigrant families and lead in building more inclusive and just policies which foster innovation and advance our collective economic and community growth.”