This collection contains letters and documents pertaining to Cope's research on the history of Charles Mason, Jeremiah Dixon, and the Mason-Dixon Line. Most of the letters are to English researchers, but included are some typescripts of original letters by Mason and Nevil Maskelyne. Cope published numerous articles on this topic, many printed by the American Philosophical Society.

This is a collection of Cope's articles, papers, notes, lectures, notebooks, and some correspondence. There is much on his research pertaining to Charles Mason and Jeremiah Dixon, and other topics in the history of science on which he wrote. The collection includes lecture notes and three bound notebook volumes on mechanics from his study at the University of Berlin under Max Planck from 1912 to 1913. There are 11 additional bound volumes, all relating to physics, including: Minutes of meetings of the Department of Physics, University of Pennsylvania (1910-1919), two volumes on the history of physics, and a volume of data on the radiometer as a measurer of electric current. The collection also contains notes on electric circuit theory lectures (1924-1925) by J.R. Carson, notes on lectures on relativity (1921) by Albert Einstein, lectures by W.F.G. Swann (1928), and information about the Pennsylvania Academy of Science, and on radiation (1909). There is significant correspondence from Lionel G. Dixon and Victor Englehardt.