The boundary line between Pennsylvania and Maryland, as run before the Revolution (1764-1767) by two English astronomers named Charles Mason and Jeremiah Dixon
the border between the states of Maryland and Pennsylvania in the US. It divided the states of the South, where it was legal to own slaveS, from the states of the North, where it was illegal, until the end of the American Civil War. Some people still consider it to be a dividing line between the North and South of the US. Originally, the boundary between Maryland and Pennsylvania. The 233-mi (375-km) line was surveyed by Charles Mason and Jeremiah Dixon in 1765-68 to define the disputed boundaries between the land grants of the Penns, proprietors of Pennsylvania, and the Baltimores, proprietors of Maryland. The term was first used in congressional debates leading to the Missouri Compromise (1820) to describe the dividing line between the slave states to its south and the free-soil states to its north. It is still used as the figurative dividing line between the North and South