Between 1870 and 1920, the clerical sector of the U.S. economy grew more rapidly than any other. As the development of large corporations affected both the scale and the content of office work, the accompanying sexual stratification of the clerical workforce blurred the relationship between the new clerical work and earlier perceptions of white-collar status. Sons and Daughters of Labor reassesses the existence and significance of the "collar line" between white-collar and blue-collar occupations during this period of clerical work's greatest expansion and the beginning of its feminization.