Between 1900 and 1945, the United States became one of the world’s leading providers of international humanitarian assistance. Collectively, and often in close partnership, US citizens, American voluntary associations and private firms, and US governmental and military officials delivered considerable aid abroad. This assistance – in the form of money, food, material supplies, and logistical support – reached millions of people in dozens of different countries and colonies. Among these recipients of US aid were survivors of a diverse array of humanitarian crises, including war, political and social upheaval, famine, and natural disasters. Across these forty-five years, US officials and citizens routinely imagined and defined these aid efforts as untarnished demonstrations of American goodwill. The reality, however, was more complex. Domestic and international politics, cultural assumptions and racial stereotypes, and uneven economic and power dynamics between American donors and aid recipients, as this chapter will show, regularly limited the humanitarian and diplomatic potential of US foreign assistance.