In September of 1918, U.S. forces engaged German forces at the Battle of Saint-Mihiel. In May of 1918, the United States achieved its first military victory of World War I at the Battle of Cantigny. In June of 1918, the Allies and the Germans fought the pivotal Battle of Château-Thierry to halt the German advance into Paris.

The Battle of Verdun was a World War I action in which the French defeated a significant German onslaught. It was one of the war's longest, bloodiest, and most brutal engagements, with over 400,000 French casualties and approximately 350,000 German casualties. 300,000 people were slaughtered.

The Battle of the Somme was a joint effort involving British and French forces aimed at achieving a decisive victory over the Germans on the Western Front. For many Britons, the ensuing fight was the most terrible and infamous incident of World War I.

Twentieth-century combat was drastically altered by developments in heavy artillery, machine guns, tanks, motorized transport vehicles, high explosives, chemical weapons, airplanes, field radios and telephones, aerial reconnaissance cameras, and fast improving medical technology and research.

Soldiers would have to rush across no-land, man's through a haze of poison gas and a barrage of gunfire and shrapnel, in order to reach the enemy. Many were killed because they were so simple to kill. After only five months of fighting in 1914, almost four million men had been killed or wounded.

On June 28, 1919, Germany and the Allied Nations signed the Treaty of Versailles, thus ending World War One. Germany was compelled to disarm, pay monetary reparations, lose territory, and relinquish all of its foreign colonies as part of the stipulations of the pact.