 The official report on the survey, issued in 1768, did not even mention their names.While the term was used occasionally in the decades following the survey, it came into popular use when the Missouri Compromise of 1820 named "Mason and Dixon's line" as part of the boundary between slave territory and free territory.In popular usage to people from the northern United States, the Mason–Dixon line symbolizes a cultural boundary between the North and the South (Dixie).