Blackburn was the son of Clarence and Vivian Mitchener Blackburn. He served in the Army during World War II, stationed in the China-Burma-India theater. He returned home and earned a bachelor's degree from Missouri Valley College. He then completed a master's in education at the University of Colorado and a doctorate in higher education at Florida State University in Tallahassee. He began his career as a men's counselor at FSU in 1952.
Blackburn was hired as assistant dean for men in 1956 and was promoted to dean in 1958. In that position he is credited with arranging behind the scenes for the peaceful enrollment of Vivian Malone and James Hood on June 11, 1963 despite Governor George Wallace's public "Stand in the schoolhouse door". He was honored for his efforts to broaden the university's service to all Alabamians.
He was promoted to dean for student development in 1968, but left to serve as vice chancellor for university resources at the University of Denver a year later. In 1978 he returned to the position of vice president for educational development at the University of Alabama, which he held until his retirement in 1990. Blackburn was twice elected president of the American Association of University Administrators and once as president of the National Association of Student Personnel Administrators.
Blackburn continued his career as a consultant, heading his own Blackburn Educational Technologies. Alabama's Blackburn Institute, founded in 1995, provides mentors to promising students. It is named in his honor.
Blackburn died in 2009. He was survived by his wife, Gloria, one daughter and two grandsons. He was a member of the Tuscaloosa Rotary Club and the Apollo Club and served on the board of directors for the Community Foundation of West Alabama. He was a member of 1st Presbyterian Church of Tuscaloosa.
- Hubbard, Russell (July 5, 2009) "Former UA administrator John Blackburn has died." Birmingham News
- 'John L. Blackburn" obituary (July 6, 2009) Tuscaloosa News