AMERICAN troubadour, folk music singer and activist Pete Seeger has died at a hospital in New York. He was 94.

Seeger's grandson, Kitama Cahill-Jackson, says Seeger died on Monday night after being hospitalised for six days.

Seeger gained fame as a member of The Weavers, the quartet formed in 1948 and had hits such as Goodnight Irene.

In the 1950s, his leftist politics got him blacklisted and he was kept off commercial television for more than a decade.

With The Weavers, Seeger helped set the stage for a national folk revival. The group - Seeger, Lee Hays, Ronnie Gilbert and Fred Hellerman - churned out hit recordings ofGoodnight Irene, Tzena, Tzena and On Top of Old Smokey.

Seeger also was credited with popularising We Shall Overcome, which he printed in his publication People's Song, in 1948. He later said his only contribution to the anthem of the civil rights movement was changing the second word from "will" to "shall", which he said "opens up the mouth better".

His musical career was always braided tightly with his political activism, in which he advocated for causes ranging from civil rights to the cleanup of his beloved Hudson River. Seeger said he left the Communist Party around 1950 and later renounced it. But the association dogged him for years.

Seeger was a 2014 Grammy Awards nominee in the Best Spoken Word category, which was won by Stephen Colbert.