Abstract
The rise of working mothers radically changed the US economy and the role of women in society. In one of the first studies of the 1975 introduction of the Earned Income Tax Credit, I find that this program increased maternal employment by 6 percent, representing 1 million mothers and an elasticity of 0.58. The EITC may help explain why the US has long had such a high fraction of working mothers despite few childcare subsidies or parental leave policies. I also find suggestive evidence that this influx of working mothers affected social attitudes and led to higher approval of working women. (JEL H24, J16, J22, J31, K34, Z13)