Labor Force The labor force is the part of a nation's population that works for pay or that is looking for a paying job. In 1800, the United States had about 2 million people in its labor force. Most of them worked on farms, most of whom were men. In 1993, about 130 million Americans were in the labor force. 96 million workers were found in large cities, 46 percent of whom were women. New Kinds of Jobs In the twentieth century, the U.S. labor force has undergone many changes. One of the most significant of these changes is in the decline in the number of blue-collar jobs and the rise in the number of white-collar jobs. A blue-collar job involves manual or outdoor labor. Blue-collar workers include factory assemblers and welders; carpenters, plumbers(水暖工), mechanics, and painters, construction workers, and truck drivers. Although the number of blue collar workers increased in the twentieth century, the future will see a declining need for such workers. Some of their jobs will be taken over by advanced automated and computerized machinery that can do certain blue-collar jobs more quickly and efficiently than people can. In contrast, a white-collar job involves work that is not chiefly manual. For example, white collar workers include accountants, engineers, teachers, lawyers, and sales personnel. In 1900, white-collar workers made up about 20 percent of the labor force; today, 67 percent of all American wage earners hold white-collar jobs. Advances in computer technology have created many new white collar jobs, such as those in programming and information processing. These changes will continue to dramatically change the nature of existing jobs. The Rise of Women in the Labor Force Until 1940, the opportunities for women to hold jobs were limited. Prejudice and discrimination(歧视)against women forced many of them to find employment as teachers, nurses, and secretaries. In 1940, women held only 25 percent of the jobs. World War II—1941 through 1945—brought about many changes in the labor force. Men were drafted to serve in the armed forces of the United States. At the same time, the country needed labor to keep factories running at full production to support the war effort. As a result, women were suddenly needed and hired even though they had been previously excluded from such jobs. Women not only repaired airplanes and land vehicles, but they also drove trucks, operated radios and machinery, and did clerical work. During the war years, the percentage of women in the labor force rose from 25 percent to 35 percent. Married women, many of whose husbands were in the armed forces, made up the greatest number of new women workers. In 1940, fewer than half of working women were single, but by 1945 a majority of women workers were married. By the end of the war, one out of every three workers in industry and business was a woman. The Postwar Years After the war, the men who returned from the armed forces went back to the same jobs they had held prior to the war. As a result, many women lost their wartime jobs. However, not all the women who had held jobs for the first time returned to their former roles as homemakers. Women had proved they could do these jobs well. As a result, the traditional barriers against the employment of women in such industries as steel and shipbuilding started to disappear, As the postwar prosperity continued, new positions became available for the returning men and for the many women workers now in the labor force. Many women found that they enjoyed not only employment outside their homes but also the benefits of paying jobs. Many women were beginning to see work as a permanent part of their lives. By earning their own income, they became less dependent and more self-sufficient. Their independence gave them new choices and made them aware of a wider range of roles avai