Not far up Stargazer Rd is  Stargazer’s Stone where, in 1764, English astronomers Charles Mason and Jeremiah Dixon began marking the border between the colonies of Pennsylvania and Maryland. The famous Mason-Dixon Line has been the traditional dividing line between the North and South   and was known as the boundary dividing free states from slave states prior to the Civil War.  Also of interest on Embreeville Rd is the Embreeville Mill, which was originally built in 1756, 20 years before the Constitution was even signed.