Object Record

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Catalog Number 01.C.55
Object Name Marker, Boundary
Title Mason-Dixon Line Markers
Artist Lee, William M.
Date 1877
Description Crest of Calvert family of Maryland. 1877 Plaster cast of original Mason-Dixon 5-mile "Crownstone" line marker from 1763-1767.
Label These 1877 casts (01.C.54 and 01.C.55) of the original 1763 crownstone markers for the Mason-Dixon line display the arms of the Penn and Calvert families. The families argued for many years about the borders of their territories. The Penns owned what is now Delaware and Pennsylvania, while the Calverts were the proprietors of Maryland. The 1681 charter from the King of England to William Penn granted Penn land whose southern border was "the beginning of the fortieth degree" of latitude, which would have put Philadelphia within Maryland. Thus began a decades-long debate over the correct border, finally ending with the Great Chancery Suit in 1750. It was agreed that the east-west line would start 15 miles south of Philadelphia, and that the boundary would be set by surveyors. Laying out a straight-line boundary, rather than following the topography of the land, was a challenge that eluded colonial surveyors. In 1763 the Royal Society of London appointed Charles Mason and Jeremiah Dixon to supervise the project. It took four years of astronomical observations and complicated geometrical calculations for the Englishmen to establish the line. Stones were to be placed at every mile, with more elaborate stones every five miles. These crownstones showed the Penn crest on one side and the Calvert crest on the other, signaling the agreement between the two families. Mason and Dixon’s survey ended 36 miles short of its goal when they reached an area that reportedly contained hostile Native Americans. Even with the best surveying knowledge and tools at the time, the Pennsylvania/Maryland boundary drifts south and north throughout the surveyed area, showing just how difficult it was to produce accurate surveys in early America.
Material Plaster
Dimensions H-12.313 W-9 D-0.938 inches
Credit line American Philosophical Society
Search Terms surveying
navigation
18th century
eighteenth century
19th century
nineteenth century
travel