It was a constant in American television for more than a decade: Viewers could turn on their TVs and find Howard Cunningham in his armchair, reading the newspaper and providing a fatherly voice of reason to young Richie Cunningham and his friends on “Happy Days.”

Tom Bosley made the role famous during the long-running sitcom, earning a place as one of the most memorable fathers in TV history.

Bosley died Tuesday at the age of 83 after suffering heart failure at a hospital near his Palm Springs home. Bosley’s agent, Sheryl Abrams, said he was also battling lung cancer.

His death brought fond remembrances of the nostalgic ABC show, which ran from 1974 to 1984. On Saturday, TV viewers lost another surrogate parent, Barbara Billingsley, who portrayed June Cleaver in “Leave It To Beaver.”

Both shows showcased life in the 1950s — before Vietnam, Watergate and other tumultuous events of the ’60s and ’70s — when life was simpler.

“Kids were watching their parents grow up, and parents were watching themselves grow up. And that was the key to success of that show,” Bosley said in a 2000 interview.

Bosley initially turned down the offer for a costarring role in “Happy Days.”

“After rereading the pilot script,” he recalled in a 1986 interview, “I changed my mind because of a scene between Howard Cunningham and Richie. The father/son situation was written so movingly, I fell in love with the project.”

Viewers did too.

“Happy Days,” which debuted in 1974, slowly built to hit status, becoming television’s top-rated series by its third season.

TV Guide ranked Bosley’s Howard Cunningham character at No. 9 on its list of the “50 Greatest TV Dads of All Time” in 2004. The distinction puts “Mr. C,” as his character was affectionately known on the show, right alongside Ward Cleaver, Andy Taylor, Dr. Huxtable and Mike Brady as some of the best-ever TV dads.

Born in Chicago in 1927, Bosley served in the Navy before returning to his hometown to study at DePaul University. Intrigued with acting, he enrolled at the Radio Institute of Chicago and began appearing in radio dramas.