This paper reassesses American opinions and sentiments during the period of neutrality in light of the one endeavor that involved millions of Americans in the European conflict long before official U.S. belligerency: war relief. Tracing some of the “humanitarian narratives” employed in the relief campaigns for the Central Powers, the Allies, and neutral Belgium, humanitarian involvement, it will be argued, not only expressed prevalent ethnic, cultural, and political affinities, but shaped American attitudes toward the different belligerents. Contrary to contemporary claims, humanitarian pursuits were never even remotely impartial, but drew Americans onto the different sides of the war like few other endeavors. Indeed, relief work must be taken serious as a force of “cultural mobilization” (Horne), which affected American “visions of the war and its outcome.” By involving Americans actively on the different sides of the European war, it helped forge discrete moral and emotional alliances across the Atlantic. In trying to understand the complicated and acrimonious process by which Americans moved from peace to war, their relief work thus deserves attention.