After six days in the hospital, folk singer and social activist Pete Seeger, who was born May 3, 1919, has died at the age of 94. Seeger was best known for his songs “If I Had a Hammer” and “Turn, Turn, Turn,” but also took part in numerous activist causes over many decades — Seeger opposed McCarthyism, marched beside Martin Luther King, Jr. and led environmental campaigns, including a cleanup of the Hudson River, and even took part in the Occupy Wall Street protests in 2011. Seeger was a contemporary of Woody Guthrie, who taught him how to jump freight trains, and with whom he became part of the left-wing Almanac Singers, who sang in opposition to the peacetime draft of 1940.

However, after the attack on Pearl Harbor, Seeger enlisted in the Army and trained as an airplane mechanic — but ended up being assigned to entertain the troops in the Pacific.

Seeger lived in Beacon, New York, with his wife, Toshi, in a cabin he mostly built himself on a cliff overlooking the Hudson River, 60 miles north of Manhattan.

Toshi died at age 91 in 2013, after nearly 70 years of marriage. Seeger is survived by a son, Daniel; two daughters, Mika Seeger and Tinya Seeger; six grandchildren; and a great-grandson.