Captain America #186, page 14 (1975)

From the 1975 story “Mind Cage!” it’s the super-secret shocking origin of Sam Wilson AKA The Falcon. The Red Skull reveals that Sam Wilson was, in reality, a criminal named "Snap" Wilson who crashed on the Island of Exiles attempting to steal a planeload of contraband from his boss. Seeing an opportunity to defeat Captain America using a sleeper agent, the Red Skull used the Cosmic Cube to give Wilson a new personality, a new set of memories, a superhuman link with Redwing and a deadly mission: kill Captain America! Whoa! How is the star-spangled simpleton going to get out of this one?