Bob Shane, who helped bring folk music to the forefront of the American cultural scene in the 1950 and 1960s as a founding member of the Kingston Trio, a group best remembered for such hits as “Tom Dooley,” “Scotch and Soda” and “M.T.A.,” died Jan. 26 at a hospice center in Phoenix. He was 85.

He had pneumonia and other ailments, said his wife, Bobbie Childress.

Mr. Shane was the last surviving original member of the Kingston Trio, which he founded in 1957 with Nick Reynolds and Dave Guard (later replaced by John Stewart). With their gentle harmonies and clean-cut looks — they favored button-down shirts with stripes — they became in their heyday one of the most popular singing groups in the United States.

They were in some ways successors to the Weavers, the folk group known for its ballads of peace and freedom and whose members, including Pete Seeger, became targets of the anti-Communist “Red Scare” in the 1950s. The Kingston Trio was assiduously less political — a point that rankled among some folk music traditionalists — but nonetheless was credited with helping lead the way for folk musicians including Bob Dylan, Joan Baez and Peter, Paul and Mary.

“Striped shirts open at the collar, crew cuts and silly grins, the crunch of happy chords and often inane lyrics adapted from the grooves of academe. In the late ’50s, you couldn’t get away from the Kingston Trio,” music critic Richard Harrington wrote in The Washington Post in 1981. “They turned America into a giant hootenanny stage, inspired hundreds of imitators and made this nation safe for folk music, even if it was a bastardized pop version.”

From the group’s founding until it disbanded in the mid-1960s, and in later forms that continued to feature Mr. Shane, the Kingston Trio was known for such numbers as “A Worried Man,” Seeger’s “Where Have All the Flowers Gone?,” “It Was a Very Good Year” (later a hit for Frank Sinatra) and “M.T.A.,’” about “a man named Charlie on a tragic and fateful day” when he is stuck on the Boston transit system because of a fare increase he cannot pay.

Perhaps their greatest hit was also their earliest hit, “Tom Dooley,” a top-selling number for which the group won its first Grammy Award, in 1958. (They were honored for best country and western performance because there was no folk category at the time. The following year, the group received a Grammy for best folk performance recognizing their album “The Kingston Trio At Large.”)

“Tom Dooley,” a ballad about a veteran of the Confederate Army who is hanged for allegedly killing his lover, is widely considered one of the most important songs in the American canon. Its success, spurred by several disc jockeys who took a liking to the Kingston Trio, stunned Mr. Shane and thrilled Capitol Records, which in time came to rely on the group for 15 percent of its sales.

Mr. Shane and his colleagues had not planned to be folk singers. Their preferred genre was the calypso music popularized by Harry Belafonte — the “Kingston” of the group’s name referred to the capital of Jamaica — but found themselves rebranded as “Tom Dooley” gained a following.

“A guy from Capitol Records gave us a check and said ‘You’re folk singers!’ ” Mr. Shane told the told the Knoxville News-Sentinel in 2001. “We looked at the check and said, ‘Yes, we are!’ ”

The Kingston Trio, and folk music in general, faded with the arrival of the Beatles and other rising groups. “Times became so much more hectic and so did the music,” Mr. Shane remarked. But he continued performing for decades, leaving many listeners awash in nostalgia.

Robert Castle Schoen — he changed the spelling of his last name in adulthood — was born in Hilo, Hawaii, on Feb. 1, 1934. His parents ran a wholesale sporting goods company in Hono­lulu, where he and Guard met at the private Punahou preparatory school. Years later, Mr. Shane recalled to the Honolulu Star-Advertiser that he sang in the school glee club and indulged his love of music playing the ukulele on the beach.

He and Guard moved to California for college, where Guard enrolled at Stanford University and Mr. Shane studied at nearby Menlo College. There he met Reynolds in what the college described as a “particularly boring accounting class” where Mr. Shane had dozed off. (Mr. Shane later introduced Reynolds to Guard.) They performed at fraternity parties and generally enjoyed a lifestyle, Mr. Shane later joked, that contrasted with their clean-cut look.

“I dropped out of college my senior year because I was playing in bars at night and couldn’t wake up for 8 a.m. classes,” he told the News-Sentinel. “That doesn’t sound like the image.”

After his studies, he returned to Hawaii and, finding himself ill-suited for his family’s business, worked as an Elvis impersonator. He told the Star-Advertiser that Reynolds called him inviting him to return to California to form a trio with Guard. And thus, he said, “the Kingston Trio was born.”

They got their start performing at venues including the Purple Onion and later at the hungry i, both celebrated clubs in San Francisco. For all the success of their many albums, Mr. Shane said they always considered themselves foremost live performers. He retired from the stage in 2004 after suffering a heart attack.

His first marriage, to the former Louise Brandon, ended in divorce. Survivors include his wife of 19 years, Bobbie Childress of Phoenix; five children from his first marriage, Jody Beale of Melbourne, Fla., and Susan Gleeson, Brandon Shane, Robin Shane and Jason Shane, all of Alpharetta, Ga.; a brother; and eight grandchildren.

Guard died in 1991, and Reynolds and Stewart died in 2008.

Besides the Kingston Trio’s musical legacy was its sartorial one, with the striped-shirt look later employed by groups including the Beach Boys. For the Kingston Trio, it was not as intentional as some fans might have imagined. “We just wore them because they were cheap,” Mr. Shane recalled, “and off the rack.”