Before World War I, a cavalry unit was an incredible asset to an army. While on horseback, mounted soldiers had the advantage of height, speed, and size.
At the opening of World War I, cavalry units were still used as a strategic advantage, but they had become nearly obsolete in the three years that it took for the United States to join the war. In that short span of time, military tactics and technology in Europe had evolved beyond horseback with the use of trenches, barbed wire, and machine guns. Nevertheless, the United States continued to train some cavalry units that would be brought overseas. Mounted soldiers would have an ever more minor role, primarily ceremonial, in World War II.