Mason-Dixon Line

The Mason-Dixon Line, also called Mason and Dixon Line, was originally the boundary between Maryland and Pennsylvania in the United States. In the pre-Civil War period it was regarded, together with the Ohio River, as the dividing line between slave-owning states south of it and free-soil states north of it.

One difference between the slave-owning states and the free states was their dependence on the cotton plantation farms for their economy, and the cheap source of labor provided by slavery.

The term Mason and Dixon Line was first used in congressional debates leading to the Missouri Compromise (1820). Today the Mason-Dixon Line still serves figuratively as the political and social dividing line between the North and the South, although it does not extend west of the Ohio River. The Mason-Dixon line was a major boundary line in the American Civil War which ended with the Gettysburg Address by President Lincoln.