<Ul> <Li> The existing east--west transpeninsular line from the Atlantic Ocean to the Chesapeake Bay, as far as its midpoint from the Atlantic . </Li> <Li> A 12 - mile (radius) circle (12 mi (19 km)) around the city of New Castle, Delaware . </Li> <Li> A "tangent line" connecting the midpoint of the transpeninsular line to the western side of the 12 - mile circle . </Li> <Li> A "north line" along the meridian (line of longitude) from the tangent point to the Maryland Pennsylvania border . </Li> <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> </Ul> <Li> The existing east--west transpeninsular line from the Atlantic Ocean to the Chesapeake Bay, as far as its midpoint from the Atlantic . </Li> <Li> A 12 - mile (radius) circle (12 mi (19 km)) around the city of New Castle, Delaware . </Li> <Li> A "tangent line" connecting the midpoint of the transpeninsular line to the western side of the 12 - mile circle . </Li>

Map of the united states with mason dixon line