This summer training program provided the base of a greatly expanded junior officers' corps when the country entered World War I. During that summer, many well-heeled young men from some of the finest east coast schools, including three of the four Roosevelt sons, attended the military camp. When the United States entered the war, in April 1917, the armed forces offered commissions to the graduates of these schools based on their performance. The National Defense Act of 1916 continued the student military training and the businessmen's summer camps. It placed them on a firmer legal basis by authorizing an Officers' Reserve Corps and a Reserve Officers' Training Corps (ROTC).