[2] After the December 7, 1941 attack on Pearl Harbor, he left high school early to join the United States Marine Corps for World War II.

[2] On July 21, 1944, Riley was leading a rifle squad from Company L, 3rd Battalion, 9th Marine Regiment in an assault against a Japanese machine gun emplacement on the island of Guam when he was severely wounded.

[4] He played the part of a hidden Japanese soldier who surprises the main characters, which required him to wear heavy camouflage makeup.

[2] While pursuing his education, he worked as an insurance broker and became active in Democratic Party politics.

[2] Beginning in 1951, Riley taught courses in economics and political science at Little Rock University.

[2] In 1957, he was appointed associate professor of history and political science at Ouachita Baptist University in Arkadelphia, Arkansas.

[2] A highly regarded instructor, Riley was promoted to full professor in 1958 and chaired the university's social science division from 1960 to 1974.