Soviet spying in the U.S. goes way back. One of the most informative and well-written autobiographies one can ever read is Witness, by Whittaker Chambers, published in 1952. One learns from Chambers, who had been a Soviet spy himself and soon came to see for himself the evil that was the Soviet Union, how the Soviets operate in the U.S. and he names and describes the activities of some of the high-ups in the U.S. government who were Soviet spies. The Alger Hiss case might be familiar to students of U.S. history. Witness is a classic “must-read” for anyone who wants to understand the early start timeline and the movers behind the slide toward socialilsm
WITNESS is also an interesting read because you could say that Chambers was one of the first of the hated neo-cons. He went from being a communist spy to being an anti-communist who worked for many years with Bill Buckley at NATIONAL REVIEW.
One thing these archives reveal is just how penetrated the US State Department is/was....
Check out “Spy Catcher” (1987) by Peter Wright, former asst. dir. of MI5 in England. Also the spy novels of John Le Carre. I almost never saw my father who was away many nights fighting to keep Communists from taking over is white collar union in the New York metropolitan area. Communists were actively trying to take over unions in major east and west coast ports in the late 40s (Harry Bridges).