Tibbs died Nov. 23 at his home in Chicago, Huffington Post reported.
After his release from prison, Tibbs became an anti-death-penalty advocate. He served as director of membership and training for Witness to Innocence, an organization of exonerated death row inmates founded by Sister Helen Prejean, author of "Dead Man Walking."
David Lowe, WTI's executive director, in a column in the Huffington Post called him "a sage, a poet, a leader and the nicest person you could ever meet, with an intellect, a spirit and a commitment that inspired all of us."
In 1974, Tibbs was charged in Fort Myers with raping Cynthia Nadeau, 16, and killing the man she was hitchhiking with, Terry Milroy, 27. He became a suspect after Nadeau changed the description of her attacker to match Tibbs.
Tibbs was convicted by an all-white jury after a two-day trial and given a death sentence. His case attracted the attention of folksingers Pete Seeger and Joan Baez and writer Studs Terkel before his conviction was overturned by the state Supreme Court in 1976 and he was released in 1977.
Prosecutors finally dropped the charges against him in 1982, calling the case "tainted from the beginning and the investigators knew it."