In tracing the rise of the modern idea of the American “new woman,” Lynn Dumenil examines World War I’s surprising impact on women and, in turn, women’s impact on the war.Telling the stories of a diverse group of women, including African Americans, dissidents, pacifists, reformers, and industrial workers, Dumenil explores both the roadblocks and opportunities they faced.By using a gendered approach to the war, she offers a complex rendering of the ways in which the United States mobilized for the coming battle and how American women helped support the largest military endeavor in the nation’s history. Arguing that in contrast to prevailing notions that military service defines citizenship, Dumenil shows how women activists staked their claim to loyal citizenship by framing women’s war work as industrial workers, home-front volunteers, overseas nurses, and support personnel as “the second line of defense.”Extensively researched and drawing upon popular culture sources as well as archival material, The Second Line of Defense offers a comprehensive study of American women and war and frames them in the broader context of the social, cultural, and political history of the era.