Star Gazers' Stone
One of the most important surveying markers in the United States, and perhaps, the world, is located in an otherwise unassuming field at Embreeville in Newlin Township in Chester County, Pennsylvania. That marker is the Star Gazers' Stone, which is the land marker that was used in 1764 by 18th century astronomers Charles Mason and Jeremiah Dixon to determine the true boundary between Pennsylvania and Maryland. At the time, the colonies of Maryland and Pennsylvania had a disputed border thanks to competing royal charters of the time. Maryland and Pennsylvania both claimed the land between the 39th and 40th parallels according to the charters granted to each colony, and this would have included the City of Philadelphia. The issue was unresolved until the British Crown intervened in 1760, ordering Frederick Calvert, 6th Baron Baltimore to accept a border agreement signed in 1732. As part of the settlement, the Penns and Calverts commissioned the team of English astronomers...