California has the largest work force in the nation and the greatest number of employed workers. During the 1970s, California's work force also grew at a higher annual rate than that of any other state. According to Bureau of Labor Statistics (BLS) provisional estimates, in July 2003 the seasonally adjusted civilian labor force in California numbered 17,635,700, with approximately 1,166,500 workers unemployed, yielding an unemployment rate of 6.6%, compared to the national average of 6.2% for the same period. Since the beginning of the BLS data series in 1980, the highest unemployment rate recorded was 11.0% in February 1983. The historical low was 4.7% in February 2001. It is estimated that in 2001, 5.4% of the labor force was employed in construction; 13.0% in manufacturing; 5.2% in transportation, communications, and public utilities; 18.6% in trade; 5.4% in finance, insurance, and real estate; 26.0% in services; 14.0% in government; and 2.7% in agriculture.
The unemployment rate during the 1970s and early 1980s ranged from the 1973 low of 7% to a high of 9.9% in 1975 and 1982. From 1967 to 1976, an average of 226,000 Californians entered the labor market each year, but the economy generated only about 175,000 jobs annually, so unemployment rose steadily.
The labor movement in California was discredited by acts of violence during its early years. On 1 October 1910, a bomb explosion at a Los Angeles Times plant killed 21 workers, resulting in the conviction and imprisonment of two labor organizers a year later. Another bomb explosion, this one killing 10 persons in San Francisco on 22 July 1916, led to the conviction of two radical union leaders, Thomas Mooney and Warren Billings. The death penalty for Mooney was later commuted to life imprisonment (the same sentence Billings had received), and after evidence had been developed attesting to his innocence, he was pardoned in 1939. These violent incidents led to the state's Criminal Syndicalism Law of 1919, which forbade "labor violence" and curtailed militant labor activity for more than a decade.
Unionism revived during the depression of the 1930s. In 1934, the killing of two union picketers by San Francisco police during a strike by the International Longshoremen's Association led to a three-day general strike that paralyzed the city, and the union eventually won the demand for its own hiring halls. In Los Angeles, unions in such industries as automobiles, aircraft, rubber, and oil refining obtained bargaining rights, higher wages, and fringe benefits during and after World War II. In 1958, the California Labor Federation was organized, and labor unions have since increased both their membership and their benefits.
The US Department of Labor reported that in 2002, 2,454,000 of California's 13,983,000 employed wage and salary workers were members of unions. This represented 17.5% of those so employed, up from 16.2% in 2001. The national average is 13.2%. In all, 2,639,000 workers (18.9%) were represented by unions. In addition to union members, this category includes workers who report no union affiliation but whose jobs are covered by a union contract.
Of all working groups, migrant farm workers have been the most difficult to organize because their work is seasonal and because they are largely members of minority groups, mostly Mexicans, with few skills and limited job opportunities. During the 1960s, a Mexican-American "stoop" laborer named Cesar Chavez established the National Farm Workers Association (later the United Farm Workers Organizing Committee, now the United Farm Workers of America), which, after a long struggle, won bargaining rights from grape, lettuce, and berry growers in the San Joaquin Valley. Chavez's group was helped by a secondary boycott against these California farm products at some grocery stores throughout the US. When his union was threatened by the rival Teamsters Union in the early 1970s, Chavez got help from the AFL-CIO and from Governor Brown, who in 1975 pushed through the state legislature a law mandating free elections for agricultural workers to determine which union they wanted to represent them. The United Farm Workers and Teamsters formally settled their jurisdictional dispute in 1977.