The Mason-Dixon Line (or, originally, "Mason and Dixon's line") is the southernmost boundary that divided Pennsylvania from Maryland. The line was set at c.39 degrees 43' 26" north by the two British surveyors (and astronomers) Charles Mason and Jeremiah Dixon, who marked out the land between 1763 and 1767 at the behest of William Penn and Lord Baltimore. Before the Civil War, the line represented the division between the Southern pro-slavery and the Northern free states. Nowadays it represents the informal division between the North and the South. The line is one of the possible etymological sources for the terms "Dixie" and "Dixieland."
Oscar Wilde (1854-1900)