William Penn became the largest private landowner in the world when Charles II granted him the 45,000 square miles of what is now Pennsylvania in 1681. An early champion of religious freedom, Penn also was among the few Europeans to deal fairly with the original inhabitants of his lands. Nevertheless, his royal charter conflicted with earlier lands deeded to Lord Baltimore, prompting a survey that resulted in the iconic Mason-Dixon Line dividing Maryland and Pennsylvania. This catalog features early Pennsylvania deeds and grants, important maps, and documents related to the border dispute.