During the first half of the 20th century, the US introduced state laws that imposed restrictions on women's labor market opportunities. This so-called `protective legislation' included minimum wage laws for women, maximum hours laws, requirements to provide chairs for female employees, and restrictions on working the night shift. Eventually, these laws were lifted in the 1960s and 1970s through a series of Acts and Supreme Court rulings, such as the Equal Pay Act of 1963 and Title VII of the Civil Rights Act in 1964. In this paper, we investigate the political economy of both the introduction and the repeal of these laws. Specifically, we investigate the hypothesis that labor market competition from women was the main driver of political change. To do so, we first use a political economy model to spell out the mechanism. Second, we show that when calibrated to US data, the model explains both the rise and fall of protective labor legislation remarkably well. Third, we use new and comprehensive cross-state data to provide empirical evidence for the mechanism and contrast these findings to alternative explanations.