<Li> Should any land within the 12 - mile circle fall west of the north line, it would remain part of Delaware . (This was indeed the case, and this border is the "arc line".) </Li> <P> The disputants engaged an expert British team, astronomer Charles Mason and surveyor Jeremiah Dixon, to survey what became known as the Mason--Dixon line . It cost the Calverts of Maryland and the Penns of Pennsylvania £ 3,512 9 / - (9 shillings 0 pence) to have 244 miles (393 km) surveyed with such accuracy . To them the money was well spent, for in a new country there was no other way of establishing ownership . </P> <P> The Mason--Dixon line is made up of four segments corresponding to the terms of the settlement: </P> <Ul> <Li> the tangent line </Li> <Li> the north line </Li> <Li> the arc line </Li> <Li> the 39 ° 43 ′ N parallel </Li> </Ul>

Line that divided north and south in civil war