From Wikipedia

World War One - American Legacy

The American Expeditionary Forces or AEF was the United States Armed Forces sent to Europe in World War I. During the United States campaigns in World War I the AEF fought in France along side British and French allied forces in the last year of the war, against Imperial German forces. The AEF helped the French Army on the Western Front during the Aisne Offensive ( at Chateau Thierry and Belleau Wood ) in June 1918, and fought its major actions in the Saint-Mihiel and Meuse-Argonne Offensives during the fall of 1918.

Officers of the American Expeditionary Forces and the Baker mission

U.S. President Woodrow Wilson initially planned to give command of the AEF to General Frederick Funston, but after Funston's sudden death, Wilson appointed Major General John J. "Black Jack" Pershing in May 1917; Pershing remained in command for the entire war. Pershing insisted that American soldiers should be well-trained before going to Europe. As a result, few troops arrived before 1918. In addition, Pershing insisted that the American force would not be used merely to fill gaps in the French and British armies, and he resisted European efforts to have U.S. troops deployed as individual replacements in decimated Allied units. This attitude was not always well received by the Allied leaders who distrusted the potential of an army whose previous fighting experience was acquired in "colonial" type expeditions ( Philippines, Mexico, Cuba ).

However, by June 1917, 14,000 U.S. soldiers had already arrived in France, and by May 1918 over one million U.S. troops were stationed in France, half of them being on the front lines. Since the transport ships needed to bring American troops to Europe were scarce at the beginning, the army pressed into service cruise ships, seized German ships, and borrowed Allied ships to transport American soldiers from New York, New Jersey, and Newport News, Virginia. The mobilization effort taxed the American military to the limit and required new organizational strategies and command structures to transport great numbers of troops and supplies quickly and efficiently. The French harbors of Bordeaux, La Pallice, Saint Nazaire and Brest became the entry points into the French railway system which brought the US forces and their supplies to the front. American engineers in France built 82 new ship berths, nearly 1000 miles of additional standard-gauge tracks and 100,000 miles of telephone and telegraph lines.

The first American troops, who were often called "Doughboys," first landed in Europe in June 1917. However the AEF did not participate at the front until late October 1917, when the 1st Infantry Division, one of the best-trained divisions of the AEF, entered the trenches near Nancy.

Pershing wanted an American force that could operate independently of the other Allies, but his vision could not be realized until adequately trained troops with sufficient supplies reached Europe. Pershing established facilities in France to train new arrivals for combat. The AEF had landed in France in 1917 without field artillery or automatic weapons and had to turn to the French to complete its equipment. Particularly appreciated were the French canon de 75, the canon de 155 C modele 1917 Schneider and the canon de 155mm GPF. All three were eventually manufactured in the USA, beginning in mid 1918. American aviation units received the SPAD XIII and Nieuport 28 fighters and the US tank corps used the French Renault FT17 light tanks. The FT17 was also built under licence in the USA beginning late in 1918.

Following the U.S. First Infantry Division, three additional U.S. Divisions, including the 42th Infantry Division with its 69th Infantry Regiment, entered the battlefields in March 1918. The rest followed at an accelerating pace during the spring and summer of 1918. At the beginning, during early 1918, the few battle-ready U.S. divisions were deployed with French and British units to defend relatively quiet sectors of their lines. After the first AEF victory on the 28th of May 1918 at Cantigny, by the 1st U.S. Division, Pershing worked towards the deployment of a US field Army.

US Army and Marine Corps troops played a key role in helping stop the German thrust towards Paris, during the Second Battle of the Marne in June 1918 (at Chateau-Thierry and Belleau Wood). The first major and distinctly American offensive was the reduction of the Saint Mihiel salient in September 1918. During the Battle of Saint-Mihiel, beginning September 12, 1918, Pershing commanded the American First Army, comprising seven divisions and more than 500,000 men, in the largest offensive operation ever undertaken by United States armed forces to date. This successful offensive was followed by the Meuse-Argonne offensive, lasting from September 26 to November 11, 1918, during which general Pershing commanded more than one million American and French combatants. In these two military operations, Allied forces recovered more than two hundred square miles (520 km²) of French territory from the German army. By the time the Armistice had suspended all combat on November 11, 1918, the American Expeditionary Forces had evolved into a modern, combat-tested army.Many future US military leaders, such as George Patton and Douglas MacArthur, were veterans of the AEF.