The Steadicam was first used in the Best Picture-nominated Woody Guthrie biopic Bound for Glory (1976), debuting with a shot that compounded the Steadicam’s innovation: cinematographer Haskell Wexler had Brown start the shot on a fully elevated platform crane which jibbed down, and when it reached the ground, Brown stepped off and walked the camera through the set. This technically audacious and previously impossible shot created considerable interest in how it had been accomplished, and impressed the Academy enough for Wexler to win the Oscar for Best Cinematography that year. It was then used in extensive running and chase scenes on the streets of New York City in Marathon Man (1976), which was actually released two months before Bound for Glory. It landed a notable third credit in Avildsen’s Best Picture-winning Rocky (1976), where it was an integral part of the film’s Philadelphia street jogging/training sequences and the run up the Art Museum’s flight of stairs, as well as the fight scenes (where it can even be plainly seen in operation at the ringside during some wide shots of the final fight). Garrett Brown was the Steadicam operator on all of these.
The Shining (1980) pushed Brown’s innovations even further, when director Stanley Kubrick requested that the camera shoot from barely above the floor. This prompted the innovation of a “low mode” bracket to mount the top of a camera to the bottom of an inverted post, which substantially increased the creative angles of the system, which previously could not go much lower than the operator’s waist height. This low-mode concept remains the most important extension to the system since its inception.
Update: Here’s Brown talking about the Steadicam and his career. And here’s Stanley Kubrick’s introduction to the Steadicam, via a letter from a colleague. (via @poritsky & @LettersOfNote)