Harper was one of eight siblings, and one of a pair of twins born to John Henry and Mattie Shirley Harper of Northport. He graduated Tuscaloosa County High School in 1937 and worked at a series of jobs from the Tuscaloosa Olan Mills Studio to an aircraft parts supplier in Birmingham. He earned a degree in business management from the Business College of Birmingham in 1950 and took a job with the Reichhold Chemical Plant in Holt, where he worked for 30 years, retiring as director of purchasing for the Southeast region.
During his working career he returned to his family home, the 1837 Shirley Place in Northport and became interested in preservation issues. He supported the relocation of Tuscaloosa's Old Tavern when it was threatened by the construction of the Hugh Thomas Bridge on Lurleen Wallace Boulevard. He went on to found several organizations, including the Friends of Historic Northport.
Harper was selected as Tuscaloosa County Citizen of the Year in 1974 and "Preservationist of the Year" by the Alabama State Historical Commission in 1979. In his honor Northport declared "Marvin Harper Day" on his 80th birthday in 1999.
- Morton, Jason (April 25, 2009) "Historian’s passion for the past will be irreplaceable, friends say." Tuscaloosa News
- "Marvin Lee Harper" obituary (April 26, 2009) Tuscaloosa News