American Military History, Volume 2 by Richard W. Stewart

Prior to March 1918 Pershing's efforts to create a distinct Ameri- can ground combat force had been checked by the shortage of trans- portation available for troops and the objectives and demands of the Allies. In December 1917 only 183,000 American soldiers were in France, comprising parts of five divisions and performing various ser- vice support functions. During the first three months of 1918 the number of Americans doubled, but only an additional two combat divisions had arrived. However, after April 1918 the various shipping arrangements with the Allies, especially the British, had begun to pay dividends; American troops began to pour into Europe. At the end of June over 900,000 Americans had arrived in France, with 10,000 arriving daily.

In early July the AEF had reached the million-man mark, with twenty-three combat divisions (an equivalent of almost fifty Allied divisions). Six of the AEF's divisions had seen combat over the previous two months: two of those were holding segments of active front lines; four were in reserve positions. The 4th Division joined those in reserve. Six other divisions were training in the American sector around Chaumont, and another five were training with the British behind the front lines in the north. Four more were brigaded with French divisions for training along quiet sectors of the line, while the regiments of the 93d Division served with French divisions.