Of course, nobody listened. “Despite the Crown’s mandate, Pennsylvania created Lancaster County, clearly extending south of the border as claimed by Maryland,” writes trivia expert Dan Lewis.

It all started with a bad map. In the 1600s ... five-year survey that would finally determine the border between Maryland and Pennsylvania. For more information on Thomas Cresap, the Penn-Calvert ...

Hailed as a groundbreaking technical achievement, it came to symbolise the border between the Civil War North and South, separating free Pennsylvania from slave-owning Maryland. But who were the ...