This dissertation is a history of women, war, and the law in twentieth-century America. In particular, it focuses on four landmark decisions of the U.S. Supreme Court: United States v. Schwimmer (1929); Reid v. Covert, first adjudicated in 1956 and then adjudicated again (and reversed) in 1957; Griswold v. Connecticut (1965); and Rostker v. Goldberg (1981). These cases have never before been examined side-by-side, because they traverse multiple domains of constitutional law and multiple, overlapping domains of immigration law, military law, and criminal law as well. This dissertation, however, argues that the Court’s decisions in Schwimmer, Reid, Griswold, and Goldberg all hinged on the same, basic question: namely, in what ways and by what means were women obliged—and not obliged—to serve their country in time of war? What’s more, the dissertation argues that the four decisions answered this question in wildly different—and sometimes diametrically opposed—ways, necessarily complicating our understanding of how American women (and American men, for that matter) worked to lay claim to the rights and obligations of twentieth-century citizenship.The dissertation begins in the aftermath of the First World War, when the U.S. was abruptly thrust into a new position of international authority—and subsequently became entangled in an almost-endless number of military conflicts around the globe. Beginning in this same period, American women also became increasingly, more intimately involved in both the U.S. military and broader projects of state violence—and a long-assumed distinction between prototypically male citizen-soldiers, on the one hand, and quintessentially female civilians, on the other, fell steadily apart. This dissertation analyzes and interrogates these large-scale (and primarily extra-legal) developments and unearths connections—between America’s military fortunes and the closer-to-home battles fought at the U.S. Supreme Court—that many other legal historians have failed to recognize and draw out. At the same time, the dissertation makes clear that constitutional doctrine followed no clear-cut, linear progression: across these four cases, the Court intervened to demarcate women’s distance from war just as often as it recognized—or imagined—women’s proximity to the same. There was no easy path to sex equality, charted out through armed conflict or otherwise, and sometimes no path to equality at all. Instead, in Schwimmer, Reid, Griswold, and Goldberg, the Court trafficked in contradictions, indulged in legal fictions, and gave rise to unintended consequences that we’re still living with today. Chapter 1 focuses on several resident alien women who were denied naturalization—all for refusing to bear arms in defense of the United States—in the decades between the First and Second World Wars. Chapter 2 focuses on two service wives—both of whom, while stationed overseas in the early postwar period, killed their military-officer husbands—and then fought to be tried by civilian juries (rather than by military courts-martial) for their crimes. Chapter 3 examines the Cold War origins of the constitutional right to privacy. Chapter 4 examines the contested constitutionality of the all-male military draft, from the Vietnam War era through the early 1980s.