(I)The U.S. Air Force was not officially created until after the Second World War. (II) But it had existed under other names since the beginning of the century. (III)It was started under the name of the Army Air Forces in 1907, taking the name of the Aviation Service during the First World War. (IV) When the United States entered World War I in 1917, the Aviation Service had only thirty-five pilots. (V)It was in 1947 that the U.S. Air Force was established as a separate branch of the military.