E problem of the Negro worker touches l every aspect of the Nation's life. Two major contributions to that understanding in this decade have been Gunnar Myrdal's An American Dilemma. Of this complex problem, the writer has selected as one area for intensive investigation the treatment of Negro-American workers by the AFL and the CIO in the San Francisco Bay Area. Although the black artisan in the South outnumbered the white 100,000 to 20,000 at the close of the Civil War, the bulk of the four million slaves had been engaged in agriculture and domestic service. Ninety percent were still in these two categories in 1890. The few who had broken out of these occupational ruts were, in the main, strike breakers. The Negro who found himself shut out of the job because he couldn't get in the union and shut out of the union because he couldn't get the job was a willing strike breaker. He helped defeat the white worker's eight-hour-day-crusade and broke his strikes in the mines, on the docks, in the stockyards, in the clothing factories, among the teamsters, on the railroads, in the metal trades, and in the steel mills. The black worker's dependence upon the slave owner in days of bondage was easily transferred to dependence upon the employer in post-war days of freedom. Agriculture and domestic service gave him no union experience and for decades he allied himself with management against the union in the struggles of the labor movement. Furthermore he was encouraged to break strike by his own leadership. Ministers, YMCA secretaries, and Urban League officials actually recruited strike breakers from their Negro-American clientele. White unionists naturally resented what they contemptuously referred to as Nigger-scabs, and color solidarity was long delayed in the labor movement. The United Mine Workers and the International Ladies' Garment Workers, however, helped to bridge the chasm by admitting colored strike breakers to their unions even after their strikes had been defeated. As strike breaking paid off with skilled jobs and union experiences in a dozen major industries outside agriculture and domestic service, Negro-Americans gradually abandoned the practice. A second phenomenon even more helpful to the Negro-American than strike breaking has been the labor vacuum. When workers have been in great demand, color caste has temporarily receded and new job opportunities have come to Negro-American workers. In California the vacuum has not been limited to of world war, but began in 1850, following the discovery of gold, to draw the Chinese, Japanese, Filipinos, and Mexicans in chronological order to take the jobs the NorthEuropean-Americans did not want. The minorities were welcomed at first during economic boom periods, but during bust periods were denied entry, one after another, by exclusionist legislation punctuating various points in 84 years of racioeconomic agitation. The Negro-American came to California late in time when the labor vacuum of World War II brought him by the thousands. He has not yet come in great numbers, however, and even in 1949 Philadelphia had three times as many Negro-Americans as the entire State of California. So has New York City. A significant percentage of the thousands drawn to the San Francisco Bay Area by the war-time labor vacuum have come into contact with the labor unions, however, many for the first time. Some of the AFL unions shut out the NegroAmerican. Others relaxed the pre-war barriers and let him in. Many locals initiated their first NegroAmerican as a result of the World War II manpower shortage. A few AFL unions had been admitting Negro-Americans for years and continued to admit increased numbers during the emergency production period. A total of 163 AFL locals were contacted in the San Francisco Bay Area in this study. They reported 195,951 members, 18,953 of whom were Negro-American, a 9.6 percentage. The Laborers, the Culinary Workers, the Molders, the Building Service Employees, and the Carpenters accounted for 55 percent of the Negro workers reported by