Prior to 1949 , each branch had their own day .
Shortly after World War II , the Department of Defense decided to consolidate the observance for all 5 branches on one day at President Truman 's insistence .
Prior to 1949 , each branch had their own day but shortly after World War II , the Department of Defense decided to consolidate the observance for all 5 branches on one day at President Truman 's insistence .