America entered World War I in 1917, with General John Pershing in command. The Great War had been raging since 1914. Though horses, cannons, and rifles were still in use on the battlefield, this war employed trucks, tanks, planes, and rapid fire weapons such as the "Browning Automatic Rifle". It was the first modern war. America’s young soldiers, called Doughboys, lifted Europe’s morale but were untrained in this new large-scale warfare on foreign soil. Pershing kept them out of battle until trained and ready. He retained command of U.S. troops rather than let his soldiers replace French or British soldiers.