Mason and Dixon's Line

Mason and Dixon's Line, so called after English engineers who surveyed it 1764-67; is the boundary separating Maryland from Pennsylvania and Delaware; during the Civil War it was inaccurately regarded as dividing the slave-holding from the free States, Maryland and Delaware both recognising slavery.

Definition taken from The Nuttall Encyclopædia, edited by the Reverend James Wood (1907)

Mason, William * Maspero, Gaston Camille Charles
Mary, Queen of Scots
Maryland
Masaccio
Masai
Masaniello
Mashonaland
Mask, Iron
Maskelyne, Nevil
Mason, Sir Josiah
Mason, William
Mason and Dixon's Line
Maspero, Gaston Camille Charles
Massachusetts
Massage
Massagetæ
Massena
Massey, Gerald
Massillon, Jean Baptiste
Massinger, Philip
Masson, David
Masso`rah