Blacklisting and subsequent career

In the early 1950s, Prager was blacklisted.^[2] In March 1953, former screenwriter Bart Lytton, told the House Un-American Activities Committee that Prager was among the persons he had seen at Communist Party meetings.^[3]

In August 1955, Prager and other performers refused to answer questions when called before the Committee, saying that "I believe that what I think and what I say and with whom I associate is not this committee's concern."^[4] In July 1956, Prager was one of seven witnesses, including playwright Arthur Miller, who were cited for contempt of Congress of Congress by the House of Representatives. The other six included stage actress Sarah Cunningham, her husband John Randolph, and actors Lou Polan and George Tyne.^[5]

Critic Howard Kissel recounted in 1998 that the backers were wary of casting Prager for the play. The director George Abbott called a meeting of the creative staff and told them of the backers' concerns. He decided to retain Prager.^[2] According to a 1976 newspaper account, Abbott decided to renew Prager's contract early in 1955 so that he would not be fired when he appeared before the committee. According to Kissel, Prager was given a run of the play contract in 1954 despite his blacklisting,^[2][6]

He subsequently began directing with Neil Simon's Come Blow Your Horn in 1961. Additional theatre directing credits include Bravo Giovanni, Minnie's Boys, Don't Drink the Water, and 70, Girls, 70.

Prager's television directing credits include The Love Song of Barney Kempinski for ABC Stage 67, Car 54, Where Are You?, and The Patty Duke Show. For producer Sidney Pink, Prager directed two films in Europe: Madigan's Millions the first film to star Dustin Hoffman, and Bang Bang Kid starring Tom Bosley and Guy Madison.