Crystal Catherine Eastman was an American lawyer, antimilitarist, feminist, socialist, and journalist. She was a leader in the fight for women's suffrage, a co-founder and co-editor with her brother Max Eastman of the radical arts and politics magazine The Liberator, co-founder of the Women's International League for Peace and Freedom, and co-founder in 1920 of the American Civil Liberties Union. In 2000, she was inducted into the National Women's Hall of Fame in Seneca Falls, New York.

Max Forrester Eastman was an American writer on literature, philosophy and society, a poet and a prominent political activist. Moving to New York City for graduate school, Eastman became involved with radical circles in Greenwich Village. He supported socialism and became a leading patron of the Harlem Renaissance and an activist for a number of liberal and radical causes. For several years, he edited The Masses. With his sister Crystal Eastman, he co-founded in 1917 The Liberator, a radical magazine of politics and the arts.