By his own estimate, Budenz spent some 3,000 hours explaining the Party's "inner workings" to the FBI, as well as testifying on 33 occasions to various committees. By 1957 he estimated he had earned approximately $70,000 for his expert testimony. Budenz was a witness at the 1949 First Amendment case "Dennis v. United States", brought by Eugene Dennis, General Secretary of CPUSA. He was also a key witness in the 1950 hearings before the Tydings Committee, which had been called to investigate charges made by Senator Joseph McCarthy that the State Department had numerous Soviet moles in its employ.