Among his publications are two major books, a History of Commodore John Barry (Philadelphia, 1903) and Catholics and the American Revolution (3 vols., Philadelphia, 1907–1911). Griffin also published monographs on the history of Old St. Joseph's and several other Philadelphia churches (1881–1882), on Bishop Michael Francis Egan, O.S.F. (1885), Thomas Fitzsimons (1887), and on the trial of John Ury (1899).
