When Walter Reed United States Army General Hospital opened its doors in 1909, the Spanish-American War had been over for a decade, World War I was in the unforeseeable future, and army hospital admission rates were steadily decreasing. The story of the founding of Walter Reed, which remained one of the flagship military health institutions in the United States until its 2011 closure, is a story about the complexities of the turn of the twentieth century. Broad historical factors—heightened imperial ambitions, a drive to modernize the army and its medical services, and a growing acceptance of hospitals as ideal places for treatment—explain why the institution was so urgently fought for and ultimately won funding at the particular moment it did. The justifications put forth for the establishment of Walter Reed indicate that the provision of publicly funded medical care for soldiers has been predicated not only on a sense of humanitarian commitment to those who serve, but on principles of military efficiency, thrift, pragmatism, and international competition. On a more general level, the story of Walter Reed’s founding demonstrates a Progressive Era shift in health services for U.S. soldiers—from temporary, makeshift hospitals to permanent institutions with expansive goals.