the chief feature of the war on the western front was
Western Front (World War I) The Western Front was the main theatre of war during the First World War. Following the outbreak of war in August 1914, the German Army opened the Western Front by invading Luxembourg and Belgium, then gaining military control of important industrial regions in France. The tide of the advance was dramatically turned with the Battle of the Marne. Following the Race to the Sea, both sides dug in along a meandering line of fortified trenches, stretching from the North Sea to the Swiss frontier with France, which changed little except during early 1917 and in 1918.
American Expeditionary Forces The American Expeditionary Forces (A. E. F., A.E.F. or AEF) was a formation of the United States Army on the Western Front of World War I. The AEF was established on July 5, 1917, in France under the command of Gen. John J. Pershing. It fought alongside French Army, British Army, Canadian Army, and Australian Army units against the German Empire. A minority of the AEF troops also fought alongside Italian Army units in that same year against the Austro-Hungarian Army. The AEF helped the French Army on the Western Front during the Aisne Offensive (at the Battle of Château-Thierry and Battle of Belleau Wood) in the summer of 1918, and fought its major actions in the Battle of Saint-Mihiel and the Meuse-Argonne Offensive in the latter part of 1918.