The Peter Guilday Papers, 55 linear feet; 110 boxes, contain personal and professional correspondence, notes, lectures, and sermons. They also contain the original documents and subject files used by Guilday throughout his career and research as a professor at Catholic University and a leading American Catholic History scholar. The majority of the collection spans his scholastic and professional career from 1904-1947. However, some of the original documents which are included date back to the 18th and 19th century. The collection is divided into three series, with photographs are interspersed throughout each series. The web address is https://libraries.catholic.edu/special-collections/archives/collections/finding-aids/finding-aids.html?file=guilday