Morgan Poitiaux Robinson, The Evolution of the Mason and Dixon Line (1902)
“ In the yet 1682, William Penn colonized the city of Philadelphia; and while Penn claimed the spirit of his charter, based upon the assumption that the map of Virginia by Captain John Smith, of the year 1608, was used in the preparation of that charter, the Baltimores insisted upon the letter of their charter, which gave them jurisdiction over the principal settlement in the Colony of Pennsylvania, so, then, Penn contended that the charter to the Baltimores granted them only to the "beginning of the fortieth parallel (what is now the thirty-ninth degree of latitude) ." ”
