In 1929, at age 15, Magdoff first started reading Karl Marx when he picked up a copy of A Contribution to the Critique of Political Economy in a used-book store.

After college, David Weintraub Head of the WPA's National Research Project assisted him to get a job with the Works Progress Administration measuring the productivity of various manufacturing industries.

Magdoff was happy[2] to leave his position with the United States Department of Commerce, on December 30, 1946, and went to work for the New Council on American Business in New York until 1948, at which time he began employment with Trubeck Laboratories in New Jersey.

This long brainstorming session on the potential obstacles the new revolution would face, sparked a mutual camaraderie that led to Magdoff also meeting with Guevara during his 1964 visit to the United Nations in New York City.

Under Magdoff's direction, the Monthly Review increasing focused on imperialism as the key unit of analysis for global development and the forces challenging neocolonialism in the Third World.

He was accused of passing information to Soviet intelligence networks in the United States, primarily through what the FBI called the "Perlo Group."

Magdoff was never indicted, but after the end of the Cold War, a number of scholars have inspected declassified documents (including those of the Venona project) from U.S. and Soviet archives.