Folk music icon Pete Seeger died on Monday at the age of 94. The well-known singer and activist was born in Manhattan in 1919. Seeger is perhaps best known for tracks such as "If I Had A Hammer," "Where Have All the Flowers Gone?" and dozens of other now-standard folk songs.

From The New York Times:

His agenda paralleled the concerns of the American left: He sang for the labor movement in the ‘40s and ‘50s, for civil rights marches and anti-Vietnam War rallies in the ‘60s, and for environmental and antiwar causes in the ‘70s and beyond. “We Shall Overcome,” which Mr. Seeger adapted from old spirituals, became a civil rights anthem.

Seeger's career began in the 1940s as a member of The Weavers as well as the Almanac Singers with Woody Guthrie. During that time he was also a member of the Communist Party, although he later abandoned that affiliation, describing himself as a "communist with a small 'c.'"

In 1955, Seeger was called before the House Un-American Activities Committee, but refused to testify. He told the committee:

I love my country very dearly, and I greatly resent this implication that some of the places that I have sung and some of the people that I have known, and some of my opinions, whether they are religious or philosophical, or I might be a vegetarian, make me any less of an American.

He was blacklisted and indicted for contempt, later sentenced to a year in prison, though he then had that sentenced overturned through an appeal. As an outspoken opponent of the Vietnam War, Seeger's song "Waist Deep in the Big Muddy" was also involved in a controversy over its censorship on CBS.

In 2004, Mother Jones wrote about Seeger as "a sunny idealist, amiable and grand fatherly, unyieldingly devoted to a few simple ideas, a nostalgist whose worldview often seems frozen in the era of his own coming-of-age." In 2011, he was an active participant in the Occupy Wall Street movement.

Seeger married his wife Toshi in 1943; she passed away last year. He is survived by his three children and six grandchildren.