George M. Cohan's popular song "Over There" accompanied Americans overseas as they joined the bloody battle that had stalemated in Western Europe for almost three years. Moving such a large army, eventually totaling two million soldiers, across an ocean was a feat not seen before, and its accomplishment emphasized that industrialized countries had the capacity to fight massive wars across the globe. In comparison to nations engaged in three years of grueling warfare, the United States faced combat mostly during the war's last six months.
However, Americans encountered unprecedented challenges fighting as part of a coalition in a new kind of war. The Great War was the world's first large-scale military struggle fought among highly industrialized countries. The mass production capabilities of the belligerents, their networks of railroads, and new rapid-firing weapons contributed to the deadlock on the European front lines. Both sides dug into miles and miles of trenches from which neither could dislodge the other. Other new technologies such as airplanes, tanks, and poison gas were widely used in an attempt to end the standoff, but no miracle weapon could break the stalemate and end the war.
Although the struggle in the trenches was brief for Americans, it was intense. After an introduction to battle at places such as Belleau Wood and St. Mihiel in France, the United States fought the deadliest battle in its history—a seven-week offensive along the Meuse River and into the Argonne Forest on the war's Western Front. Medical advances and care for the wounded provided by organizations like the Red Cross kept many alive who might have died in earlier wars. Americans made important contributions to the Allied victory but at considerable cost.