migrant labor, term applied in the United States to laborers who travel from place to place harvesting crops that must be picked as soon as they ripen. Although migrant labor patterns exist in other parts of the world (e.g., Africa, Australia, Canada, Europe, and South America), none compares with the extent and magnitude of the system in the United States. Migrant laborers may travel on their own or they may be transported by a contractor who has agreed to supply the farmer with the needed workers. They may be urban dwellers who go on the land only for the season or migrants whose only means of living is to follow the crops from one place to another. Efforts to enforce sanitary conditions, prevent child labor, and protect the workers from exploitation met with only slight success until the 1960s.
In the 1930s, a combination of droughts, the depression, and the increased mechanization of farming prompted a migration of small farmers and laborers from Arkansas, Kansas, Oklahoma, and Texas to the W United States. It was estimated that this type of permanent migrant worker, without home, voting privileges, or union representation, numbered more than 3 million. John Steinbeck's The Grapes of Wrath is a dramatic representation of the life of those migrants. In World War II another type of migrant worker sprang into being with the need for labor in the defense industries. These uprooted workers experienced housing problems, but they were protected by wage and hour laws that did not apply to agricultural labor.
Since the 1940s, thousands of workers each year have been brought into the United States from foreign countries, principally from Mexico. Migrant labor, which remains almost exclusively agricultural, continues to receive little legal protection. However, in the mid-1960s, under the leadership of Cesar Chavez, organization of migrant workers began in the West, mainly in California. In 1970, after years of strikes, marches, and a nationwide boycott, more than 65% of California's grape growers signed contracts with the AFL-CIO's United Farm Workers Organizing Committee headed by Chavez. That organization, which became a full-fledged union as the United Farm Workers (UFW) in 1972, had some success in negotiating contracts in other states as well. However, it found itself locked in a fierce struggle with the Teamsters Union, which also claimed to represent migrant laborers and succeeded in renegotiating many of the UFW's contracts in California. The Teamsters' attempt to break up the UFW led to many strikes and some violence. The rivalry also significantly reduced UFW's membership (down to 24,000 members in 1996, compared to 100,000 in the late 1970s).
See C. McWilliams, Factories in the Field (1939, repr. 1971); D. Nelkin, On the Season (1970); W. A. Cornelius, ed., The Changing Role of Mexican Labor in the U.S. Economy (1989); D. Cohen, Braceros (2011).