Siegel grew up in Detroit and studied photography at the New Bauhaus in Chicago, under the school's founder László Moholy-Nagy.

[1][2] There he studied under the school's founder, László Moholy-Nagy, as well as György Kepes, until 1938, when he returned to Detroit.

[3] He then began working as a photojournalist for the New York Times, and took journalism assignments for newspapers, magazines, and government agencies for the next several decades.

[2] After the war, he returned to the New Bauhaus (by then the IIT Institute of Design) as an instructor, at the request of Moholy-Nagy.

He left in 1955 to work in photojournalism full-time, and returned in 1965; in 1971, he was named president of the IIT Institute of Design.