For more information about David J. Kennedy
This site contains a searchable Database of the Kennedy Collection.
All of the pieces of Kennedy's collection mentioned on this website are availiable at The Historical Society of Pennsylvania
Someone at The Free Library of Philadelphia created bound journals of photocopies of pieces from Kennedy's Collection.
Kennedy is also mentioned on this website, which documents historic views of Guelph, Canada.
Philadelphia: Three Centuries of American Art, Bicentennial Exhibition, April 11- October 10, 1976. Philadelphia, Philadelphia Museum of Art, 1976. (Contains the most biographical information about Kennedy that I could find).