During the world war I, The group that contributed the largest numbers to the U.S. combat units that fought in Europe during was: draftees
Draftees refers to a group of people that required by law to join military services. During the world war I, there was a massive needs to increase the amount of military forces. Which is why government created the selective service act of 1917 In order to draft men with a certain criteria to join the army to fight in the world war I.