Sam Carr was born in Tomachpol, Ukraine on 7 July 1906 and immigrated to Canada in 1924. He lived in Regina and Winnipeg until he moved to Montreal in 1925 and became an organizer for the Young Communist League along with Fred Rose
. In the 1940s, Carr became the editor of a communist publication, The Clarion,
and eventually became the party organizer for the Labour Progressive Party. When the RCMP began detaining suspects on 15 February 1946, Carr skipped the country to avoid capture. He was later detected and arrested in New York city several years later and was the last of the suspects to be convicted when he was found guilty of conspiracy to obtain a false passport in April 1949. Along with Fred Rose
, Carr was one of the principal recruiters for the Soviets in Canada.