The essay offers an overview of the humanitarian activities of the American Red Cross in Europe during the Great War and its aftermath. In this period, the American Red Cross (ARC) solidified its status as one of the United States' most important humanitarian aid organizations. Between 1914 and the early 1920s, tens of thousands of Americans volunteered for service with the ARC, both in the United States and in the organization's overseas commissions. U.S. citizens, meanwhile, contributed hundreds of millions of dollars to the ARC's war relief campaigns. With these funds, ARC personnel delivered humanitarian assistance to millions of U.S. and European soldiers. They also provided aid to innumerable civilian men, women, and children, targeting both emergency relief needs and longer-term health and social welfare issues. By the early 1920s, this ARC assistance had reached roughly two-dozen countries, spreading throughout Europe, Russia, and the Near East. Collectively, these efforts represent one of the most significant examples of American philanthropic activity during the Great War era.