Joseph Gregg attended City College of New York and at the outbreak of war in Spain he travelled to that country and drove a truck for the Comintern affiliated Loyalists of the International Brigades for the duration of the war. Upon return to the United States Gregg found employment with Robert Miller who was operating the Hemisphere, a weekly newsservice on Latin American affairs.
In 1941 Gregg managed the Export Information Bureau, formerly the Hemisphere, in Washington D.C., a failing publication which was taken over by the Coordinator of Inter-American Affairs (CIAA) in 1942 at which time Gregg began working with his old employer, Miller, in the CIAA.
Gregg and Earl Browder, General Secretary of the CPUSA, met with Elizabeth Bentley in Mary Price's apartment in Washington D.C., the rendezvous point for delivering stolen material from the Perlo group to courier for transmission to the Soviet Union, at the time Mary Price was seeking to end her involvement in wartime espionage on behalf of the Soviet Union. Gregg provided information on U.S. naval intelligence, military intelligence, and FBI reports on Soviet and Communist activities in Central and South America.
Gregg transferred to the United States Department of State in 1944, and lied on his application about his involvement with the International Brigades. Gregg at one time had been a member of the Rockefeller Commission.
- Elizabeth Bentley deposition 30 November 1945, FBI file 65-14603.
- Ladd memo to Director, 7 December 1945, serial 118, Ladd memo to Director 12 December 1945, serial 235, FBI Silvermaster file.
- FBI Washington Field Office report, 11 March 1946, serial 674, FBI Silvermaster file.
- FBI Silvermaster file
- Alexander Vassiliev’s Notes on Anatoly Gorsky’s December 1948 Memo on Compromised American Sources and Networks