Hackney graduated from Ramsay High School in 1952 and earned his bachelor's degree at Vanderbilt University in 1955. He served in the U.S. Navy from 1956 to 1959 before joining the faculty of the U.S. Naval Academy. He went on to study American history at Yale University, completing a master's and a PhD under C. Vann Woodward. His scholarly interests were the American South, utopian projects, and the Civil Rights movement. His 1969 book Populism to Progressivism in Alabama won the Albert J. Beveridge Prize awarded by the American Historical Association.
Hackney began his career as a lecturer at Princeton University and helped create its program in African-American studies. He served as university provost form 1972 to 1975, when he accepted an appointment to become president of Tulane University in New Orleans, Louisiana. He left in 1980 and became president of the University of Pennsylvania in 1981. He stepped down from that role in 1993 to accept an appointment by President Bill Clinton to chair the National Endowment for the Humanities. During his tenure he initiated a " National Conversation on American Pluralism and Identity." In 1997 he returned to Penn as Boies Professor of United States History. He retired from teaching in 2010 and moved to Martha's Vineyard.
Hackney died in 2013 from amyotrophic lateral sclerosis (ALS). He is buried at West Chop Cemetery in Vineyard Haven.
- Hackney, Sheldon (1969) Populism to Progressivism in Alabama. Princeton University Press ISBN 0691045917
- Hackney, Sheldon (1971) Populism: The Critical Issues. Little Brown Books.
- Hackney, Sheldon (1999) One America Indivisible: A National Conversation on American Pluralism and Identity. Washington D.C.: National Endowment for the Humanities
- Hackney, Sheldon (2002) The Politics of Presidential Appointment: A Memoir of the Culture War. Montgomery: New South Books. ISBN 1588380688
- Hackney, Sheldon (2005) Magnolias without Moonlight: The American South from Regional Confederacy to National Integration. Piscataway , New Jersey: Transaction Publishers ISBN 0765802937
- "Sheldon Hackney, 79" obituary (September 12, 2013) Vineyard Gazette
- "Remembering Sheldon Hackney" (September 13, 2013) National Endowment for the Humanities - accessed September 14, 2013