Did Back to the Future really almost star Eric Stoltz instead of Michael J. Fox?

The answer

Director Robert Zemeckis originally wanted Michael J. Fox for Marty McFly, but Fox's schedule on the NBC sitcom Family Ties made him unavailable. Eric Stoltz was cast instead and filmed for five weeks beginning in November 1984. However, Zemeckis and producer Bob Gale realized Stoltz was playing the role too dramatically - he was a method actor bringing intensity where they needed comedic timing. They made the difficult decision to fire Stoltz and renegotiate with Fox, who agreed to an exhausting dual schedule: filming Family Ties during the day and Back to the Future from 6:30 PM to 2:30 AM. The reshoot cost an additional $3 million. The gamble paid off - the film grossed $389 million worldwide and became the highest-grossing film of 1985.