Before the United States entered the war, Nazi Germany Minister of Propaganda, Josef Goebbels, expressed his confidence and optimism in the eventual possibility of the U.S. joining the Allied side against Germany because the regular U.S. armed forces were too small and poorly equipped as to pose a threat to Hitler's Germany. As well, he laughed at the U.S. government plans to increase the number of servicemen by recruiting and training common citizens in order to create a "citizen army," a term Goebbels found preposterous and laughable. Likewise, Nazi Germany Minister of the Air Force (Luftwaffe), Hermann Göring, publicly stated that "Americans are only good at manufacturing refrigerators and razor blades."
After the Japanese attack on Pearl Harbor on December 7, 1941, millions of U.S. civilians, many young men ages 17 to 21, showed up at the recruiting offices to join the armed forces and avenge the sailors and soldiers killed in Pearl Harbor.  Throughout the course of the war, the U.S. Army alone elected and trained six million men and through relatively brief yet pretty practical and effective training programs such as the basic training program (where men learned the basics of military life and basic use of firearms) and  basic combat training for infantrymen, and the training officer program (usually taken by college students selected by the Army) that officer candidates would take at the Reserve Officers' Training Corps (ROTC).
By July 1942, the U.S. Army had managed to complete the training for the first combat-ready units that would serve as of August 1942 in the Pacific Theater of Operations (PTO) in Guadalcanal and New Guinea. The following batch of fully-trained and operational combat units would have the baptism of fire in November 1942 as U.S. troops landed in Casablanca, Morocco. As the U.S. G.I.s (government issue, nickname given to U.S. Army soldiers) first engaged in combat, they struggled to hold their own ground as their enemies were seasoned and experience in combat after years of war; however, the skills and knowledge acquired in basic training and a combat training proved valuable to help inexperienced G.I.s to quickly learn the latest warfare tips from their British allies plus they would also learn directly from their clashes with the Germans, Italians and Japanese.
In conclusion, the U.S. Army wartime training programs proved to be successful in turning citizens into combat-ready soldiers with skills that would serve them well even after the war. Furthermore, president Roosevelt issued the G.I. Bill which granted college scholarships to many World War II veterans and greatly increased the educational levels of the U.S. population in the years to come.
