Milton Wolff was born in Brooklyn, New York in 1915. He dropped out of high school and joined the Civilian Conservation Corps, although he was let go for protesting the poor treatment of an injured friend. Wolff was fighting in Spain by age 21, and by 22 he was the ninth commander of the Lincoln Brigade. The previous eight commanders had either been killed or wounded. It was the last attempt to support Spain against the revolt led by General Francisco Franco. During his time in Spain, Wolff became friends with Ernest Hemingway, who was there as a reporter to write fiction on the conflict.