California’s first four assemblywomen began their historic tenure in 1919 in the state’s Forty-Third Session of the Legislature. They joined a growing number of women elected to state legislatures before ratification of the federal suffrage amendment. Entitled to run for office when enfranchised by the state in 1911, and elected in 1918, Esto Broughton (Stanislaus County), Grace Dorris (Kern County), Elizabeth Hughes (Butte County), and Anna Saylor (Alameda County) challenged the all-male exclusivity of the legislature by creating political space for women’s equal inclusion and bringing the value of their diversity as women into lawmaking. Intersectionality informs this history, because assemblywomen’s status as white, middle-class women enabled them to ally with men of similar status and to focus on progress for women of their race and class. Contributing to the history of early women in elective politics, and drawing on newspaper and state legislative records, this article explores how the assemblywomen downplayed their gender in self-presentation but focused on it in legislation. The first four women, moreover, voted on two amendments to the U.S. Constitution, beginning the legislative session with ratification of the Eighteenth Amendment and concluding the year with a vote for the Nineteenth Amendment. Their efforts as California’s first legislators solidified the value of women’s diversity in the legislature and, by voting to extend woman suffrage nationwide, they ensured women’s continued inclusion in elective politics.