Leave It to Jane was the musical that proved the Princess formula could be a success even in much larger venues; it was also the Princess musical most directly shaped by World War I. I begin this chapter by discussing the social movements that dominated American popular culture in 1917: neutrality under the increasing pressure of naval blockades and the arms trade, the dangers of alcohol and lax morals among American youth, and the inescapable industrialization of modern life. I also consider the role of comedy—part escapism, part realism—in serving the American public through these crises. Again describing the plot in detail, I evaluate the ways in which Leave It to Jane functions as a Little Theatre “problem play” responding to the wartime zeitgeist. The nostalgic alma mater, the militant football cheers, and all songs in between position the ensemble more prominently than in previous Princess musicals. The communal warmth of a college campus mimics the spirit of self-sacrifice and fraternity that enveloped a country under imminent threat of war. The subverted gender roles demonstrated that young women could be athletic, active, and assertive, and attractive. Even the show’s novelty songs position the modern American as the golden ideal against which anything foreign is ridiculous and/or obsolete. Most importantly, both the primary and secondary leads’ romantic relationships are advanced almost entirely through song. Kern’s score has taken on new emotional weight as the stakes rise.