A City Guide To Yucheng Qu for Contemporary sources put the total cost of World War I at around $200 billion, with $40 billion in additional property damages, and $65 billion in lost production. The cost in human life was immeasurable. Approximately 117,000 Americans died as a result of World War I and another 204,000 were injured. At least 15 million people died in a disastrous flu epidemic during the war. Aftermath of the war. When the Armistice was signed in November 1919, the American economy slowed down and prices soared. Despite this, the United States continued to have war-related expenses. A City Guide To Yucheng Qu 2016.