Mason & Dixon: Their Line And Its Legend


Jeremiah Dixon, always the lesser-known partner in the survey and other joint ventures with Mason, soon dropped out of history. He died in 1779. Charles Mason, for all his accomplishments as a scientist, fell into financial and physical decline in the early 1780’s. In the fifteen years following the project in the New World, he had completed his star charts, which were to become a standard navigation aid, and had made various scientific expeditions for the Royal Society. Also, during this time, he assumed the responsibilities of a wife and family. But the remuneration for what was primarily a scholarly career was then, as now, inadequate for the demands of a growing household and declining health. Late in 1786 Mason turned up in Philadelphia with his wife and eight children. What prompted this return to the scene of his definitive project of twenty years earlier can only be conjectured. Apparently he had some hope that Franklin might be able to find a place for him. He may have thought of participating in the survey of western lands now opening up; but he died a few weeks after his arrival.

With the years, much of the work of the surveyors inevitably became undone. Some of the original boundary stones were removed, either by builders who found them handy for incorporating into a wall, or by farmers who found them in the way while plowing, or occasionally by someone who felt that his property was on the wrong side of the state line. In the western region, where earthen mounds had formed the markers, the elements tended to obliterate them. The first of several resurveys was begun in 1849 to re-establish the complex boundary relations at the northwest corner of Delaware. More refined instruments and more accurate astronomical and geodetic data for the mathematical evaluation of observations disclosed slight errors in the work of Mason and Dixon, but Lieutenant Colonel James D. Graham of the U.S. Army Engineers, who supervised the 1849 resurvey, made a point of praising “the surprising accuracy” of the 1764 observations. Colonel Graham’s reaction was to be echoed in 1885, when the U.S. Coast and Geodetic Survey confirmed the western extension of the line which divided Pennsylvania from what had become, in the meantime, West Virginia.

Another resurvey was run in 1902—again under joint commissions from Maryland and Pennsylvania and with the aid of the U.S. Coast and Geodetic Survey. Where practicable, the original markers were reset in concrete; otherwise, new stones were put in place with the dates 1766/7 and 1902 carved, respectively, on their eastern and western faces. The result, stated the commissioners in their final report, was to confirm the remarkably small degree of error in the work of Mason and Dixon, which was carried on through wild country without the benefit of modern instruments. For the two English scientists who laid down the line, this should be a sufficient memorial.

A Short Time Between Drinks