Ace Rothstein is based on casino boss Frank "Lefty" Rosenthal, whose career inspired the movie.

Nicky Santoro was based on Tony "The Ant" Spilotro, SPOILER: who with his brother, was killed in a cornfield and buried. :SPOILER

Cameo: [ Frank Cullotta] the grey-haired hitman in sunglasses near the end of the movie. He was the chief lieutenant of Tony "The Ant" Spilotro in the late '70s, early '80s. Cullotta entered the Witness Protection Program before the "cornfield incident" took place and was not present, unlike Marino. - IMDB

While the movie begins by stating it is based upon a true story, it never names the actual casino involved. The Tangiers casino is fictional. The story is actually based upon the history of the Stardust casino, a fact well documented in the Vegas history books. Scorsese discreetly documents this fact via the soundtrack, in which the song "Stardust" is heard three different times. An instrumental version plays during Ace and Ginger's wedding and a vocal version is heard during the scene where Remo asks Marino if Nicky and Ginger are having sex and also during the very end of the final credits.
- IMDB