An English Quaker from County Durham, in 1763 Jeremiah Dixon became the joint architect of one of the most important boundaries in history: the Mason-Dixon line between Pennsylvania and Maryland, which still marks the division between the North and the South in the United States. The author is a Quaker who lives near Dixon's home at Cockfield in County Durham, and his book offers unique insights into the life and achievements of 'Jerry the Astronomer'. Illustrated.