<Li> First President to be assigned a Secret Service codename . </Li> <Li> First sitting President to visit Germany . He visited the Allied - occupied Germany . </Li> <Li> First President to serve in World War I. Truman served as an officer of the American Expeditionary Forces and commanded a unit of the 129th Field Artillery Regiment . He saw combat service in the Meuse - Argonne Offensive . He was discharged from the army in 1919, with the rank of major . He remained affiliated with the United States Army Reserve until 1953 . He was promoted to lieutenant colonel in 1925 and colonel in 1932 . </Li> <Li> First President to have a television set installed in the White House . </Li>

Who was the first american president to be photographed