Excerpt from Paul Rose, The Manchester Martyrs (1970), p. 127
… in April, 1967, the Dungannon Observer published the following remarkable report from Pittsburgh, a city very much like Manchester on the other side of the Atlantic Ocean:
Letters of Manchester Martyrs Found in Pittsburgh, USA William P. Allen's Farewell Messages to Family Presented to Library of Irish Center by Tom McGuigan Jr. I was present in the home of Mr. Robert Gariby, great grandnephew of William P. Allen, one of the three Manchester Martyrs (Allen, Larkin and O'Brien), when Mr. Gariby turned over to Dr. James McKaveney five letters which were written by Allen to members of his family on the eve of his execution. These letters will be hermetically encased, and put on permanent display in the library of the new Irish Centre in Pittsburgh, Pa.
William Allen’s Papers were donated to the University of Pittsburgh in May 1977 and may be viewed here.