The men lacked experience in warfare
To build a huge army that would march the large standing armies of Germany and Austria, which were to the numbers of 9 million, the USA had to quickly build an army, when Wilson and the nation,could no longer play dumb to Germany unrestricted submarine warfare. as a result, congress,enacted the selective recruitment act that required all men, aged between 21-28 year to register with local drafts boards, as the war raged, the years were raised to 45 years. These men had not served in the army and were simply sent to battle after very little training.
