The Clancy Brothers were an influential Irish folk group, which initially developed as a part of the American folk music revival. Most popular in the 1960s, they were famed for their trademark Aran jumpers and are widely credited with popularising Irish traditional music in the United States and revitalising it in Ireland, paving the way for an Irish folk boom with groups like the Dubliners and the Wolfe Tones. The Clancy Brothers, Patrick "Paddy" Clancy, Tom Clancy, and Liam Clancy, are best known for their work with Tommy Makem, recording almost two dozen albums together as The Clancy Brothers and Tommy Makem. Makem left in 1969, the first of many changes in the group's membership.
The Clancy Brothers' mother read news of the terrible ice and snow storms in New York City and sent Aran sweaters for her sons and Tommy Makem to keep them warm. They wore the sweaters for the first time at the Blue Angel nightclub in Manhattan, simply as part of their regular winter clothes. When the group's manager Marty Erlichman, who had been searching for a special "look" for the group, saw the sweaters, he exclaimed, "That's it! That's it! That's what you're going to wear." Ehrlichman requested that the group wear the sweaters on their upcoming television appearance on The Ed Sullivan Show. After they did, the sales of Aran sweaters rose by 700% according to Liam Clancy, and they soon became the Clancy Brothers and Tommy Makem's trademark costume. On 12 March 1961, the Clancy Brothers and Tommy Makem performed for around fifteen minutes in front of a television audience of forty million people for the first time on The Ed Sullivan Show. A previously scheduled artist did not appear that night, and the Clancy Brothers and Tommy Makem were given the newly available time slot on the show, in addition to the two songs they had initially planned to do. The televised performance and the success of the Clancys' and Makem's nightclub performances attracted the attention of John Hammond of Columbia Records. The group was offered a five-year contract with an advance of $100,000, a huge sum in 1961. For their first album with Columbia, A Spontaneous Performance Recording, they enlisted Pete Seeger, one of the leaders of the American Folk Revival, as backup banjo player. The record included songs that would soon become classics for the group, such as "Brennan on the Moor", "Jug of Punch", "Reilly's Daughter", "Finnegan's Wake", "Haul Away Joe", "Roddy McCorley", "Portlairge" and "The Moonshiner". The album was nominated for a Grammy Award in 1962. Around the same time that they recorded A Spontaneous Performance, the Clancy Brothers and Tommy Makem cut their final, eponymous album with Tradition Records. By the end of 1962, they released a second album with Columbia, Hearty and Hellish! A Live Nightclub Performance, and they played an acclaimed concert at Carnegie Hall. Additionally, they were making appearances on major radio and television talk-shows in America.

Q: What kind of sweaters did they make famous?
A: Aran sweaters

Q: What was their first popular song?
A: "Brennan on the Moor", "Jug of Punch", "Reilly's Daughter", "Finnegan's Wake", "Haul Away Joe", "Roddy McCorley", "Portlairge" and "The Moonshiner".

Q: What brought about their success?
A: The televised performance
What else helped in their success?
they enlisted Pete Seeger, one of the leaders of the American Folk Revival, as backup banjo player. The group was offered a five-year contract with an advance of $100,000, a huge sum in 1961. The televised performance and the success of the Clancys' and Makem's nightclub performances attracted the attention of John Hammond of Columbia Records. the success of the Clancys' and Makem's nightclub performances The televised performance and the success of the Clancys' and Makem's nightclub performances attracted the attention of John Hammond of Columbia Records.
The televised performance and the success of the Clancys' and Makem's nightclub performances attracted the attention of John Hammond of Columbia Records.