 Stachel was imprisoned at Danbury Federal Penitentiary in Danbury, Connecticut from July 2, 1951 to March 1, 1955 in connection with his Smith Act conviction.Upon his release Stachel was returned to the top leadership of the CPUSA, first as a member of the CPUSA's National Trade Union Commission.He was elected to the party's governing National Executive Committee in 1957.