Nuclear Museum Logo
Nuclear Museum Logo

National Museum of Nuclear Science & History

Steve Nelson

Chairman of the San Francisco Communist PartyUniversity of California, Berkeley

Soviet Atomic Bomb ProgramSpy

Steve Nelson was an American agent of the Communist Party.

Nelson joined the party in 1925 when he was living in western Pennsylvania. When he moved to the bay area in 1942 he became chairman of the San Francisco branch of the Communist Party. 

Almost immediately after taking that position, he became very involved in trying to uncover the work being done on the atomic bomb project at the University of California, Berkeley.  He befriended many of the physicists working on the project with Communist leanings. In March of 1943 he met with one of them, Joseph Weinberg, who gave him information regarding the bomb. Nelson would eventually pass this information on to agents of the Soviet government. 

Steve Nelson's Timeline
1903 Jan 1st Born in Subocka, Croatia.
1925 Joined the Communist Party.
1942 Became Chairman of the San Francisco branch of the Communist Party.
1943 Mar Obtained atomic bomb information from Joe Weinberg.
1950 Arrested under the Pennsylvania Sedition Act.
1993 Dec 11th Died in Cape Cod, MA.

Related Profiles

Martin Kamen

University of California, Berkeley

Martin Kamen (1913-2002) was a Canadian-American physicist. Kamen was seemingly destined for a landmark career in physics when he arrived at the Radiological Laboratory at the University of California, Berkeley in 1936.

Owen Chamberlain

Los Alamos, NM

Owen Chamberlain (1920-2006) was an American physicist and winner of the 1959 Nobel Prize.  He joined the Manhattan Project in 1942 after his graduate studies were interrupted by World War II.

Norman Goldstein

Chicago, IL

Norman Goldstein was a junior physicist at the University of Chicago’s Metallurgical Laboratory (“Met Lab”) during the Manhattan Project.

C. Donald Shane

University of California, Berkeley

Charles Donald Shane was an American astronomer and personnel director at the Berkeley Rad Lab and Los Alamos during the Manhattan Project.