Ralph Waite, who played the kind and steady patriarch of a tight-knit rural Southern family on the TV series “The Waltons,” died Thursday, his manager said. He was 85.

His manager, Alan Mills, confirmed the death but said he did not know the cause. He said Mr. Waite had been in good health and was working.

Mr. Waite appeared last year in episodes of the series “NCIS,” in which he played the father of star Mark Harmon’s character. He also appeared in “Bones” and “Days of Our Lives.”

On “The Waltons,” which aired on CBS from 1972 to 1981, Mr. Waite starred as John Walton in a gentle family drama set in the Blue Ridge mountains of Virginia. Richard Thomas played his oldest son, John-Boy, an aspiring novelist.

“The Waltons,” which followed the family’s triumphs and setbacks through the Great Depression and World War II, was narrated by its rich-voiced creator, Earl Hamner Jr., who based it on his family memories.

Ralph Waite, shown at top left in this 1975 cast photo from “The Waltons, died Feb. 13 at 85. (AP)

The show was a TV rarity, a respectful depiction of Southern country life, and proved so popular that it overpowered its hit comedy competition, NBC’s “The Flip Wilson Show.”

Ralph Harold Waite was born June 22, 1928, in White Plains, N.Y. He served in the Marine Corps before earning a bachelor’s degree in 1952 from Bucknell University in Lewisburg, Pa., and a master’s degree from Yale University’s divinity school.

He was an ordained Presbyterian minister and served at churches in New York before becoming disillusioned with formal religion. After working at a publishing house, he turned to acting in his 30s.

Mr. Waite appeared on the stage before moving on to the big screen with roles in 1967’s “Cool Hand Luke” and 1970’s “Five Easy Pieces,” in which he played the brother of Jack Nicholson’s character.

Mr. Waite received Emmy nominations for “The Waltons” and his performance in the 1977 ABC miniseries “Roots.”

Mr. Waite’s role as a steady TV dad in the CBS drama was in contrast to his personal life, which was marked by alcoholism, he told the Desert Sun newspaper in Palm Springs, Calif., in 2010.

“I was a caring, responsible father to all of these kids,” he said. “But I was drinking the night before and being a drunk on the side.”

He gave up drinking in the 1970s.

In 1990, Mr. Waite ran unsuccessfully as the Democratic challenger to a four-term Republican incumbent in the U.S. House of Representatives.

In 1998, he vied for the congressional seat left open after Republican Sonny Bono, another performer who turned to politics, died in a skiing accident. Bono’s widow, Mary, won the special election.

Mr. Waite’s first two marriages ended in divorce. Survivors include his third wife, Linda East.