He was 83 when he died Thursday, his son, Andrew, told the Los Angeles Times Friday.
Stuart was a four-time Emmy Award winner and cousin of Marvel Comics mastermind Stan Lee.
Among Stuart's many documentaries are "Wattstax," "The Making of the President 1960," "Four Days in November," "The Unfinished Journey of Robert Kennedy," "Life Goes to the Movies" and "Man Ray: Prophet of the Avant Garde."
The New York native's TV projects include the movies "Bill," "Ruby and Oswald" and "The Triangle Factory Fire Scandal," as well as the TV mini-series "The Chisholms." He also served as an executive producer of the 1980s version of the TV series "Ripley's Believe It or Not!" the Times said.