The widespread participation of women in paid labor outside of the home and in the highest echelons of society would have been unheard of a century ago. This paper documents this dramatic change in women's social and economic status and argues that it was determined both by contemporaneous demand factors and by the characteristics, expectations, and social norms regarding work and family of different cohorts of women. History suggests that change in women's labor force experiences may be slow because it must await the entry of new cohorts of women (and also of men) into the labor market.