<P> By BLS definitions, the labor force is the following: "Included are persons 16 years of age and older residing in the 50 States and the District of Columbia who are not inmates of institutions (for example, penal and mental facilities, homes for the aged), and who are not on active duty in the Armed Forces ." </P> <P> The labor force participation rate is the ratio between the labor force and the overall size of their cohort (national population of the same age range). In the West during the later half of the 20th century, the labor force participation rate increased significantly, largely due to the increasing number of women entering the workplace . </P> <P> In the United States, there were three significant stages of women's increased participation in the labor force . During the late 19th century through the 1920s, very few women worked . Working women were often young single women who typically withdrew from labor force at marriage unless their family needed two incomes . These women worked primarily in the textile manufacturing industry or as domestic workers . This profession empowered women and allowed them to earn a living wage . At times, they were a financial help to their families . </P> <P> Between 1930 and 1950, female labor force participation increased primarily due to the increased demand for office workers, women participating in the high school movement, and electrification which reduced the time spent on household chores . In the 1950s to the 1970s, most women were secondary earners working mainly as secretaries, teachers, nurses, and librarians (pink - collar jobs). </P>

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