The attached chart was pulled from a 1931 U.S. Government study indicating the number of soldiers in the U.S. Army each month from 1917 through 1919, and the number of Doughboys who were deployed in Europe.
"When the World War One was declared there were 200,000 men in the Army. Two-thirds of these were Regulars and one-third National Guardsmen who had been called to Federal service for the duty along the Mexican border. When the war ended this force had been increased to 20 times its size and 4,000,000 men had served."
Click here to read more statistics about the American military of the First World War.
Click here to read an interview with the World War I American fighter pilot Eddy Rickenbacker.
Read about the Doughboy who loved Paris
Some decades later it was discovered that a full sixty percent of the invalided Doughboys were mentally deficient, and the Army was unable to screen them out - you can read about that here
