During World War I, the Second Battle of the Somme, the first major German offensive in more a year, begins on the western front. After five hours of bombardment from more than 9,000 pieces of German artillery, the poorly prepared British Fifth Army was forced into retreat in France's Somme River region. For a week, the Germans pushed toward Paris, shelling the city from a distance of some 80 miles with their "Big Bertha" cannons. However, the poorly supplied German troops soon became exhausted, and the Allies halted their advance as French artillery knocked out the German guns besieging Paris. On April 2, U.S. General John J. Pershing sent American troops down into the trenches to help repulse the German offensive. It was the first major deployment of U.S. troops in World War I.
By the time the Somme offensive ended, on April 4, the Germans had advanced almost 40 miles, inflicted some 200,000 casualties, and captured 70,000 prisoners and more than 1,000 Allied guns. However, the Germans suffered nearly as many casualties as their enemies and lacked the fresh reserves and supplies enjoyed by the Allies following the American entrance into the fighting. Several thousand American troops fought alongside the British and French in the defense of Paris.