An excellent recounting of the revelations of what was going on with Soviet espionage in the U.S. in the 1930s and 1940s is the 1999 book, Venona: Decoding Soviet Espionage in America, which documents the U.S. VENONA project, running from 1943 to 1980, to decrypt piles of Soviet diplomatic and intelligence traffic which had been sloppily encrypted with re-used “one-time” pads. A collection of VENONA decrypts may be read on the U.S. National Security Agency’s “VENONA Documents” Web site. All 3000 decrypted and translated documents have now been published.
An excellent revisionist biography of Joseph McCarthy informed by, among other sources, the VENONA decrypts, is M.Stanton Evans’ Blacklisted by History. The fury with which the establishment went against McCarthy after his May, 1950 speech in Wheeling, West Virginia, is instructive when pondering their bared-fangs assault on Donald Trump over a conversation regarding Ukraine.