Because of the transient nature of migrant workers, trends in migrant farm labor are difficult to track, though it's estimated that from 125,000 to more than 1 million migrant agricultural workers currently work in the United States. One of the most significant periods for migrant farm workers occurred in the 1930s, when hundreds of thousands of displaced farmers from the country's southern Great Plains moved west—mostly to California—to escape harsh conditions in Oklahoma, Texas, Missouri, and Arkansas. There, severe drought, economic depression, unsustainable farming practices, and the advance of mechanized farming all combined to displace tenant and subsistence farmers. The area became known as the Dust Bowl because wind storms caused huge dust storms that eroded the depleted soil, devastating the area and making farming all but impossible.
The federal depression-era Agricultural Adjustment Administration also played a financial role in worsening the plight of southern Plains tenant farmers by paying benefits directly to their landlords, instead of to the tenant. This allowed tenant farmers to be replaced by laborers, or by tractors.
At the same time, California was experiencing a shortage of farm labor for a variety of reasons. Among them was a drive by the state to stem the flow of illegal immigrants from Mexico and to break the cycle of Mexican laborers depending on public relief when harvest periods were over. In 1930, relief agencies, particularly those in Los Angeles, initiated a program, better known as repatriation, that would pay a small sum per capital to Mexicans who would accept a free ride back to Mexico. By 1933, some 75,000 Mexican workers had returned home, although the majority remained in the state. At the same time, the economic depression that had taken hold beginning in 1929 grew worse. In 1930, only one-fifteenth as many people came to the United States from Mexico seeking work.
The resulting labor shortage coincided with the dire conditions in the southern Plains, and the stage was set for the Dust Bowl migration, immortalized by John Steinbeck's novel The Grapes of Wrath.
The Dust Bowl farmers had reason for hope when they pulled up stakes and moved to California. Lured by California's temperate climate, a year-round growing season, more diversified crops, and enticed by advertising that promised jobs in the fields, the impoverished farmers and their families headed west along Route 66, expecting a virtual paradise in the state's vast agriculture industry. Known pejoratively as "Okies" because some 20% of the migrants came from Oklahoma, the migrants were often disappointed to learn that California—suffering itself from the nation's economic depression—was not the paradise they had expected.
Estimates of the total number of Dust Bowl immigrants to California range from 300,000 to 600,000, with the majority arriving between 1935 and 1937. Some sources have estimated that the number reached 3 million. Their impact on the state was especially problematic because the migrants concentrated in sparsely populated rural communities—primarily in the fertile San Joaquin and Sacramento valley regions. There, desperate for employment, they worked for as little as 20 cents per hour; less than the Mexican laborers they had replaced, but more than they had typically earned back home. Still, they taxed relief agencies and aroused public ire. In Kern County, which saw 52,554 new arrivals between 1935 and 1940—a population increase amounting to 63%—Okies stayed in squalid camps set up along roadside ditches, amid orchards, and in river bottoms. They overwhelmed school districts, hospitals, and public services.
Starting in 1937, the Farm Security Administration established a series of well managed, though rudimentary labor camps, where workers lived in tent cabins and had access to medical care. Though "Okies" faced considerable discrimination from residents of the areas, they had come to California in search of a better life and a permanent place to call home. Rather than following the harvest season as migrant workers and traveling from town to town, they generally put down roots and never returned to the states they had left. When the nation began arming itself for World War II, many went off to fight in the war, while others found jobs in shipyards and arms factories, and as the depression lifted, most became permanent residents of California.
Most migrant farm workers in the United States today are of Latino descent, including vast numbers from Mexico and Central America. Because they rarely remain in one place for long, they often don't qualify for government aid or disability insurance and typically don't enjoy the same protections as industrial workers.
The agricultural, mining, and construction industries in California and the border states of Texas, Arizona, and New Mexico have long depended on low-cost immigrant labor, primarily from Mexico. As were the Dust Bowl refugees, Mexican immigrants—and, since the 1970s, Central American immigrants—were drawn north in search of a better life. By 1929, 65% to 85% of the fruit and vegetable crop in the Southwest was picked by Mexican labor, most of them arriving in the country without legal documentation. In 1942, as the country fought in World War II, the government established the Emergency Labor Program, also known as the bracero program, in order to control the influx and deployment of immigrant labor. By the time the program ended in 1964, some 4.6 million labor contracts had been executed, and many of the participants had established social and work contacts within the country, moving out of agriculture and into more stable work.
Another force at work in the lives of migrant workers is labor organization. As early as the 1930s, leftists in the labor movement attempted to unionize workers that the American Federation of Labor considered "unorganizable" due to their mobility and lack of legal status.
Labor organization among migrant farm workers languished until 1962, when César Chávez, the son of a family of poor farm workers, founded the National Farm Workers Association (NFWA). Chávez used nonviolent tactics, including a prolonged strike against table grapes centered in Delano, California, which drew national attention on the plight of farm workers. In 1966, he led a 340-mile march from Delano to the state capital of Sacramento.
That year, Chávez signed an agreement with the Agricultural Workers Organizing Committee of the AFL-CIO to form the United Farm Workers (UFW). By 1970, the UFW had contracts with 65% of the state's grape growers and boasted 50,000 dues-paying members—the most ever represented by an agricultural union in California. Members enjoyed higher wages and also received services that included a health clinic, a health plan, and a credit union. Soon, the UFW was organizing in Florida, and by the late 1970s, the UFW boasted a membership that exceeded 100,000. Later disputes with the Teamsters Union sharply diminished UFW membership, as did disputes between Chávez' followers, some of whom accused him of nepotism. By 1996, UFW membership had dwindled to some 24,000.
Gregory, James. American Exodus: The Dust Bowl Migration and Okie Culture in California. New York: Oxford Press, 1989; Guerin-Gonzalez, Camille. Mexican Workers and American Dreams : Immigration, Repatriation, and California Farm Labor, 1900-1939. New Brunswick, NJ: Rutgers University Press, 1994; Higbie, Frank Tobias. Indispensable Outcasts: Hobo Workers and Community in the American Midwest, 1880-1930. Urbana: University of Illinois Press, 2003; McWilliams, Carey. Factories in the Field: The Story of Migratory Farm Labor in California. Berkeley : University of California Press, 2000.