When the United States joined the war on April 6, 1917, the nation’s military forces were comprised of only 200,000 soldiers. By the end of that month, only 97,000 additional men had enlisted willingly, prompting government officials to employ more aggressive recruitment tactics. The Selective Service Act was issued on May 18, 1917, requiring all male citizens aged twenty-one to thirty to register for the draft by June 6, 1917. Twenty-four million men registered for the draft and almost three million were drafted into service.
In the summer of 1917, most of these new soldiers stayed behind to receive military training, while a small group of more experienced troops headed to Europe.