The collection includes photocopies of letters by Josef Cardinal Mindszenty and an undated photograph of Pope Paul VI. The arranged correspondence dates from 1947 to 1980. There are manuscripts by a number of Hungarian emigres as well as by Pfeiffer himself. The subject files contain information on the Assembly of Captive European Nations. Among the printed materials are 49 folders of newspaper articles by or about Pfeiffer. In addition, there are seven reels of 7 1/2" audio tape containing interviews with Pfeiffer.