Battle of Saint-Mihiel, Allied victory and the first U.S.-led offensive in World War I, fought from September 12–16, 1918 . The Allied attack against the Saint-Mihiel salient provided the Americans with an opportunity to use the American Expeditionary Forces on the Western Front en masse and, for the first time, under their own command rather that under that of French generals. Although lacking some of the tactical skills of the French and British, the U.S. First Army carried the day through sheer determination, overwhelming numbers (more than a million fresh U.S. troops had arrived on the front), and its multifaceted plan of attack. The battle was also noteworthy as the first major use in the war of the U.S. Army Air Service (precursor to the U.S. Air Force) led by William “Billy” Mitchell and the aggressive tank assaults by George Patton, who boldly led his charges from the front lines and not from the rear as many other officers did during the war.

　　Erich LudendorffErich Ludendorff, c. 1930.(more)The American commander-in-chief in France, General John Pershing, had, in the main, fought off attempts to use his divisions piecemeal in support of French and British operations, preferring to hold them back to form a separate U.S. army. The attack on the Saint-Mihiel salient, a bulge in the old Verdun line that extended outward toward the Allied lines and that was 25 miles long and 15 miles deep, gave him the opportunity to use the U.S. First Army in combat for the first time. In a plan developed by a rising young lieutenant colonel, George Catlett Marshall, the American part of the assault was to be conducted by two “super” corps, each with three divisions in attack and one in reserve, marking the largest assembly of U.S. soldiers since the American Civil War. Two smaller French corps would provide support on the western part of the salient.

　　World War I Events keyboard_arrow_left

　　Battle of the Frontiers August 4, 1914 - September 6, 1914

　　Battle of Mons August 23, 1914

　　Battle of Tannenberg August 26, 1914 - August 30, 1914

　　First Battle of the Marne September 6, 1914 - September 12, 1914

　　First Battle of Ypres October 19, 1914 - November 22, 1914

　　Battle of Tanga November 2, 1914 - November 5, 1914

　　Battle of the Falkland Islands December 8, 1914

　　Christmas Truce December 24, 1914 - December 25, 1914

　　Gallipoli Campaign February 16, 1915 - January 9, 1916

　　Naval Operations in the Dardanelles Campaign February 19, 1915 - March 18, 1915

　　Second Battle of Ypres April 22, 1915 - May 25, 1915

　　Battles of the Isonzo June 23, 1915 - October 24, 1917

　　Battle of Lone Pine August 6, 1915 - August 10, 1915

　　Battle of Verdun February 21, 1916 - December 18, 1916

　　Battle of Jutland May 31, 1916 - June 1, 1916

　　Brusilov Offensive June 4, 1916 - August 10, 1916

　　First Battle of the Somme July 1, 1916 - November 13, 1916

　　Battle of Messines June 7, 1917 - June 14, 1917

　　June Offensive July 1, 1917 - c. July 4, 1917

　　Battle of Passchendaele July 31, 1917 - November 6, 1917

　　Battle of Caporetto October 24, 1917 - December 19, 1917

　　Battle of Cambrai November 20, 1917 - December 8, 1917

　　treaties of Brest-Litovsk February 9, 1918; March 3, 1918

　　Battle of Belleau Wood June 1, 1918 - June 26, 1918

　　Battle of Amiens August 8, 1918 - August 11, 1918

　　Battle of Saint-Mihiel September 12, 1918 - September 16, 1918

　　Battle of Cambrai September 27, 1918 - October 11, 1918

　　Battle of Mons November 11, 1918 keyboard_arrow_right General Erich von Ludendorff—now short of men and aware of the coming Allied offensive—had decided to withdraw from the salient to a shorter and more easily defended line to the rear. As the Germans were withdrawing, the Allies attacked. With much of their artillery not in place, the Germans were poorly prepared to maintain the front line, an advantage that the attacking Americans were quick to exploit. The American assault was aided by coordinated strafing and bombing runs; Mitchell had assembled the largest air armada of World War I, numbering more than 1,000 airplanes, and these set about relentlessly bombing German positions and reshaping the battlefront to limit avenues of escape. German fighter aces dueled in the sky with the likes of budding American aces Eddie Rickenbacker and Frank Luke. So successful was Mitchell’s air campaign that he was promoted to brigadier general after the battle.

　　The relative ease of the initial American attack came as a surprise to Pershing, and he sent orders to his commanders to speed up their advance. Prominent in the attack was the 42nd “Rainbow” Division, commanded by Brigadier General Douglas MacArthur. By September 13 lead units of the U.S. First Army had met up with Allied troops advancing from the west. Three days later, the offensive was halted, with the salient in Allied hands. The Battle of Saint-Mihiel easily convinced the British and French military leadership that the Americans were capable of operating on their own on the battlefield, independence that later had a bearing on the Americans’ taking a role in negotiations for Germany’s surrender and the subsequent peace. Pershing now dispatched his forces westward to take part in the forthcoming Meuse-Argonne offensive.

　　Losses: U.S., 7,000 casualties; German, at least 17,500, including 10,000 captured.