Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, Lauren Vogel Bam. Here ask a Southerner where the South begins, and you might get answers like where one syllable words become two or three, or where the most honored foods are grits engravy. In other words, the South should begin in Richmond, Virginia, or Lexington, Kentucky, or even Wheeling, West Virginia.
But the Mason Dixon Line, which has been regarded for two hundred years as the transition between the north and the South in the United States, turns that conventional sociological thinking upside down. The Mason Dixon Line runs between Maryland and Pennsylvania and Delaware, which are all three considered northern states. So if the Mason Dixon Line really is the dividing line between the north and south, why then does it put in Maryland in the south. The Mason Dixon Line
is not some geographical folk paw. It's the result of one of the most significant surveying achievements in North America. It was named for Charles Mason, and astronomer and Jeremiah Dixon, a surveyor who introduced surveying techniques to North America that would go on to be used to draw boundary lines for western states in the US. We spoke with Todd Babcock, a Pennsylvania surveyor and founder of the Mason and Dixon
Line Preservation Partnership. He said, in many respects, the techniques we use today are very similar to those used by Mason and Dixon. I used the analogy that Mason and Dixon used the constellation of stars to guide them, and today we use a constellation of satellites. Mason and Dixon, who were English, were hired in seventeen sixty three by the King of England to settle a land dispute between two aristocratic colonial families then headed by William Penn the
Second and Charles Calvert. The two families quarreled and fought over land for decades. The colonial landowners along the line separating the two proprietors land feared being asked to pay taxes to both the Pens and the Calverts because both families were claiming the same land. So Mason and Dixon spent fifty eight months survey being a two hundred and thirty three mile that's three seventy four kilometer stretch of
land from Philadelphia westward. It was mostly wilderness, and they established the boundaries of Pennsylvania, Maryland, Delaware, and what was then Virginia and is now West Virginia. It became a steadfast boundary. The pens were to the north with Philadelphia as their hub, and the calverts to the south with Baltimore as their hub. The Mason Dixon line also included the eighty three mile that's one hundred and thirty three kilometer north south border between what was then Pennsylvania, now
Delaware and eastern Maryland. The line starts in the southwest corner of Delaware and runs north. It was meticulous and painstaking work at that time, as the men used the stars as guidance to follow a line of latitude. Mason and Dixon, with Iroquois guides leading a traveling party of about a hundred and twenty axe men, wagon drivers and attendants, cut through virgin forest as they went westward. The men used in astronomical clock they brought from England to help
determine the ellipticity of the Earth. Babcock said it added to our understanding of the shape of the Earth and that it wasn't a perfect sphere, it was bulging in the middle, and while Mason and Dixon found that while the earth was indeed round, it had undulations. The men also used a zenith sector, which is a graduated arc of a vertical circle, paired with a telescope and plumb line.
Their tripod mounted surveying tool, known as a Bird Transit after its inventor, John Bird, was thought lost in history's dustbin, but was discovered by accident in Philadelphia, restored, and now sits an exhibit in Independence Hall. Babcock says the men painstakingly placed limestone posts, also brought from England, at each mile along the way, while crown stones were set every
five miles or eight kilometers. These crown stones were carved with the letter C on the southern side of the rock for Calvert and a P on the northern side for Pen. Some stones had the Pen coat of arms and others the Calvert coat of arms. Stones were massive and weighed as much as five hundred to seven hundred pounds that's surround two hundred and twenty to three hundred and any kilo's apiece. So when Mason and Dixon and the team got to the Appalachian Mountains around Hancock, Maryland.
They had to stop placing them because they simply weighed too much. They used wooden posts the rest of the way. They had traveled a hundred and thirty two miles that's two hundred and twelve kilometers from Philadelphia in the Mason and Dixon Line. Preservation Partnership was formed between a group of surveyors from Maryland and a group of surveyors from Pennsylvania to conduct an inventory of the original hundred and
dirty two markers. They found all but ten. Floods the Civil War, farmers cutting fields, and people using them for target practice had left many of the stones damaged or destroyed. But what about This surveying led to the Mason Dixon Line becoming the unofficial dividing line between where the North ends and the South begins. That's where politics comes in. In eighteen twenty, Maryland was the northernmost slave state. Pennsylvania
was a free state. As part of the Missouri Compromise that sought to even out the number of slave states and free states, Maryland was relegated added to the South because of its practice of slavery. The U. S Congress then declared that territories south of the Mason Dixon line were slave states, and because the South was holding tight to the idea of slavery, Maryland was the South. Slaves were free once they stepped into Pennsylvania, at least until
the Fugitive Slave Act of eighteen fifty. The Mason Dixon Line was a boundary and a symbol that still holds weight, but it's also an important historical note in the science of surveying. Every fence erected between neighbor's yards and pink ribbon tied to steel steak is a descendant of the work of Mason and Dixon. Today's episode was written by Ray Glear and produced by Tyler Plang. For more on this and lots of other topics, visit how Stuff works
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