Senator Joseph McCarthy made it his mission to purge communists from American public life - but in April 1954 he was the subject of his own congressional hearing, after allegations that he had tried to blackmail the US Army into giving preferential treatment to one of his aides. Witness speaks to Norman Dorsen, one of the Army's junior legal advisors in the Army-McCarthy hearings.

(Photo: American politician Joseph McCarthy, Republican senator from Wisconsin, testifies against the US Army during the Army-McCarthy hearings, Washington DC, 9 June, 1954. McCarthy stands before a map which charts communist activity in the United States. Credit: Getty Images)