General Karl Wilhelm Georg August von Einem (1853 – 1934), commander of the German Third Army (1914 - 1919) granted a short interview to a member of the U.S. Army General Staff concerning his observations regarding the American Army.
Attached is a small piece that explains how the draft of 1917 was conducted. Illustrated with three charts, this article provides the number of males in the U.S. at that time (54,000,000), how many had registered under the Selective Service Act (26,000,000), the percentage of the whole number who had never registered and how the onslaught of the influenza epidemic had affected the W.W. I draft.
"In the fall of 1917 the first half million came rapidly. During the winter the accessions were relatively few, and those that did come in were largely used as replacements and for special services."
Here is another account from The Enemy Order of Battle report (1919) - on this page two experienced German veterans recalled their unit's battles with the American infantry:
"American soldiers took big chances and [did so] irrespective of any danger."
Attached is a graph comparing the amount of time it took for both the British Army and the American Army to have 2,000,000 soldiers on the Western Front during World War One:
"The British sent to France many more men in their first year in the war than we did in our first year. On the other hand, it took England three years to reach a strength of 2,000,000 men in France and the United States accomplished it in one half the time."
An assortment of opinions gleaned from various interviews with German soldiers who all made remarks about the naked aggressiveness shared by the A.E.F.:
"The French would not advance unless sure of gaining their objectives while the American infantry would dash in regardless of all obstacles and that while they gained their objectives they would often do so with heavy loss of life."
Here is a page from The Enemy Order of Battle report (1919) by the subsection of the same name that was an arm of the U.S. Army General Staff. The report tells of Baccarat, a portion of the Western Front during the later part of the war that was quiet, by mutual agreement between the French and Germans - until the U.S. Army took their place in the French position - and then all Hell broke loose.