The
Mason–Dixon line, also called the
Mason and Dixon line or
Mason's and Dixon's line, was
surveyed between 1763 and 1767 by
Charles Mason and
Jeremiah Dixon in the resolution of a border dispute involving
Maryland,
Pennsylvania, and
Delaware in
Colonial America. It is still a
demarcation line among four U.S. states, forming part of the borders of Pennsylvania, Maryland, Delaware, and
West Virginia (originally part of
Virginia before 1863). Later it became known as the border between the North and South. It also became the slavery border before the
Missouri Compromise.
In popular usage, the Mason–Dixon line symbolizes a
cultural boundary between the
North and the
South (
Dixie). Originally "Mason and Dixon's Line" referred to the border between Pennsylvania and Maryland. After
Pennsylvania abolished slavery, it served as a demarcation line for the legality of
slavery. That demarcation did not extend beyond Pennsylvania because Delaware, then a
slave state, extended north and east of the boundary. Also lying north and east of the boundary was
New Jersey, where slavery was formally abolished in 1846, but former slaves continued to be "apprenticed" to their masters until the passage of the
Thirteenth Amendment to the United States Constitution in 1865.