The William Kashatus collection consists of materials compiled and/or created between 1904 and 2020 in the preparation and writing of his books and articles. This includes the biography "One-Armed Wonder: Pete Gray, Wartime Baseball, and the American Dream". Included are questionnaires and correspondence with individuals such as Bob Broeg, Bill Borst and Tim McCarver, an interview with Pete Gray conducted by Steve Svetovich, as well as correspondence between William Kashatus and various publishers regarding both his manuscripts and articles. Clippings of articles used by Kashatus in his research, as well as articles written by Kashatus on both Pete Gray and on Philadelphia Baseball and materials regarding the history of Pennsylvania's Wyoming Valley coal filds. There are different proofs and manuscripts of the book, including the primary source documentation for an early draft entitled, "Beating the Odds: An Unauthorized Biography of the One-Armed Outfielder Pete Gray". There is information on the Pete Gray Historical Marker, dedication program, and two tickets to the Red Barons and Syracuse Skychiefs, August 24, 2003.

Materials relating to his books "Macho Row", relates to the 1993 Philadelphia Phillies, published in 2017, and "Lefty and Tim", relates to Steve Carlton and Tim McCarver, published in 2022. Material includes interview transcripts, clippings, articles, correspondence.

Materials were included for three unpublished works. There is a spiral-bound book on Stan Pawloski and the Cleveland Indians. This has photocopies of articles, clippings, biography, and an interview. The second is clippings, articles, and interviews on Rocky Colavito, and the third is about Howie Bedell, and includes clippings, correspondence, and a 2012 manuscript.