President Obama heralded legendary folk musician Pete Seeger in a statement Tuesday, saying the "Where Have All the Flowers Gone?" singer helped move the "country closer to the America he knew we could be."

"Over the years, Pete used his voice – and his hammer – to strike blows for worker’s rights and civil rights; world peace and environmental conservation," Obama said. "And he always invited us to sing along. For reminding us where we come from and showing us where we need to go, we will always be grateful to Pete Seeger."

Seeger died Monday at 94, after a lengthy musical career defined by top hits and political controversies.

In the 1950s, Seeger was investigated for his ties to Communism and was summoned before the House Un-American Activities Committee. Later, he worked with civil rights leaders (introducing Martin Luther King Jr. to "We Shall Overcome") and wrote songs protesting the war in Vietnam. In his later years, Seeger was a top environmental activist.

Obama said he and first lady Michelle Obama sent their "thoughts and prayers to to Pete’s family and all those who loved him."