He studied at the Académie Julian and Académie Colarossi in Paris. He became politically active while living in Europe, and his work began to reflect his political views. After returning to the United States, he continued to work as an artist and political activist, and he became known for his caricatures and editorial cartoons.
Wolff's caricatures and cartoons were published in a variety of magazines and newspapers, including the New York World, the New York Tribune, the Boston Herald, and the Chicago Daily News. He also published several books of his work, including "The World's Worst People" (1907) and "A Gallery of Sinners" (1914).
Wolff was a vocal critic of capitalism, imperialism, and war, and his work often reflected his opposition to these social and political issues. He was also a supporter of the Socialist Party of America, and he frequently used his art to promote the party's policies and candidates.