Drawing the Mason Dixon Line

United States North Becames Yankee and the South Becomes Dixie

Aug 7, 2009

When Pennsylvania and Maryland were given to Penn and Calvert there were no natural boundaries except the Delaware Bay to the east. This was a problem for the owners.

The confusion between the two men began in 1681 when King Charles II gave William Penn the area known as Pennsylvania. Wanting a way to travel straight from his newly owned land, Penn asked his friend, the Duke of York, for the area that lays east and that will give direct access to the Atlantic Ocean. The Duke agreed.

Lord Baltimore claimed he owned the land between the 39th and 40th Parallel, the land that also claimed by Penn. Trees, rocks, and waterways determined the location of the border in the early days of the United States, however, the 39th and 40th Parallel had no natural landmark. The dispute between the two men carried on and never settled during their lifetime.

In the 1730s, the dispute between the two colonies became violent and did not cease until 1750 when King George II stepped in and settled the dispute by granting the land to the Penn family, however, where the exact border between the two colonies was unknown.

Finally, in 1763, the King of England suggested that Charles Mason and Jeremiah Dixon, two of the most respected surveyors in England, travel to Pennsylvania and Maryland and determine where the exact border is located.

Who were Charles Mason and Jeremiah Dixon

Born in April of 1728 in Weir Farm, England, Charles Mason spent his early years at the Royal Observatory in Greenwich, England. There he collected data on the “lunar of distances for deriving longitude”.

Jeremiah Dixon was born August 1733 in Cockfield, England. He was educated at Benard Castle where his life led him to meet well-known mathematician, William Emerson, and astronomers, John Bird and Thomas Wright.

In 1761, Dixon assisted mason to observe the transit of Venus from Sumatra. Their goal was to collect data that would be used to calculate the distance between the sun and the earth. The men did not make to it to Sumatra, but got to observe the transit at the Cape of Good Hope on June 6, 1761.

Sailing to Philadelphia to End the Border Dispute

Mason and Dixon arrived in Philadelphia in 1763. They immediately began to survey the north/south line that divided the Delmarva Peninsula between Pennsylvania and Maryland, which was fifteen miles south of Philadelphia. The men continued their survey by moving east to west between Maryland and Pennsylvania.

Limestone quarried in Great Britain was used as border markers was sent to Philadelphia. Engraved on the 3.5 X 5 feet stones were Ps on the northside and Ms on the southside to distinguish between the two boundaries. The stones weighed approximately 300 to 500 pounds. The stones were hauled by wagon and placed one mile apart. At every fifth mile, the Penn Coat of Arms and the Calvert Coat of Arms were displayed in place of the Ps and Ms.

Following the Mason-Dixon Line

The surveyors arrived west of the Susquehanna River in 1765. They reached the South Mountain in August and the Potomac River in September that same year.

During February and March of 1766, Mason took a break and traveled to York, Pennsylvania, Frederick, Maryland, Alexandria, Port Royal, Williamsburg, and Annapolis, Virginia.

Mason and Dixon picked up surveying again in March. They reached Sideling Hill in late April and reported “long periods of rain and snow”.

Beyond Sideling, the survey party traveled into “unbroken wilderness”. The wagons hauling the stones were unable to travel further and the men marked and used oak posts instead of the stone markers.

In the winter of 1766 and 1767, Mason and Dixon traveled back to Embreville, Pennsylvania, also known as the “Forks of Brandywine” where they had earlier set-up an observatory for stargazing.

In 1767, at Dunark Creek, near Mount Morris, Green County, Pennsylvania, and now West Virginia, Mason and Dixon were forced to end their survey by the Iroquois. This completed the surveyors’ appointment to document officially the border between Pennsylvania and Maryland.

In 1782, Alexander McClean of Fayette County, Pennsylvania finally completed the Mason-Dixon Line.

Danson, Edwin. Drawing the Line: How Mason and Dixon Surveyed the Most Famous Border in America. NY. Wiley Publishers, 2000.

Veech, James. Mason and Dixon's Line: A History. Including an outline of the boundary controversy between Pennsylvania and Virgina. Ann Arbor, University of Michigan Press, 2005.

The copyright of the article Drawing the Mason Dixon Line in Colonial America is owned by Christine Musser. Permission to republish Drawing the Mason Dixon Line in print or online must be granted by the author in writing.