Fred Silverman, who as a top executive at CBS, ABC and finally NBC was one of the most powerful people in the three-network era — a force behind the success of beloved series like “All in the Family,” “The Mary Tyler Moore Show,” “M*A*S*H,” “Laverne & Shirley” and “Hill Street Blues” — died on Thursday at his home in the Pacific Palisades section of Los Angeles. He was 82.

Julia Rossen, of the public relations concern 42West, announced his death in a news release. She said the cause was cancer.

At 25, Mr. Silverman was made head of daytime programming for CBS, and in 1970, in his early 30s, he landed the network’s top programming job, putting him in charge of the prime-time schedule.

CBS, known in the 1960s for relatively conventional comedies like “The Andy Griffith Show” and “The Beverly Hillbillies,” was looking to freshen its image, and Norman Lear and Bud Yorkin’s groundbreaking “All in the Family,” which tackled contemporary issues like bigotry with scalding humor, became a key component of that strategy.