On April 6, 1917, the U.S. declared war on Germany and formally entered World War I. By late June, American infantry troops began arriving in Europe. One thing they couldn't do without? Coffee.
"Coffee was as important as beef and bread," a high-ranking Army official concluded after the war. A postwar review of the military's coffee supply concurred, stating that it "restored courage and strength" and "kept up the morale."