The Mason-Dixon Line-what is it? Do you recollect that it had something to do with the Civil War?

Well, on this 150th anniversary of the Civil War, when films like Steven Spielberg's Lincoln are attracting a lot of buzz, it is a perfect time to dust off a long forgotten tale about the Mason-Dixon Line-it was not created to separate slave and non-slave states, no, it predated the Civil War by many years - it was created to help preserve the fledgling Pennsylvania colony by settling a festering intercolonial conflict.

The war was between the colonies of Maryland and Pennsylvania. It started in 1730. Some called it Cresap's War after Thomas Cresap, a Marylander who sold disputed Pennsylvania lands and registered them in Maryland; others call it the Conojocular War because it took place in the Conejohela Valley. This southern Susquehanna River marsh has since been flooded by construction of the Safe Harbor, Holtwood, and Conowingo dams.

In 1632, Maryland was granted a charter from King Charles I for a colony with a northern border at the 40th parallel. In 1681, William Penn received a charter from King Charles I for a colony with a southern border at the 40th parallel. Seems clear-except...

At the time, it was believed that the 40th parallel was 12 miles north of New Castle, Delaware, and several miles south of Philadelphia. Later, it was discovered that it was just north of Philadelphia. Thus, according to the original deeds, Philadelphia was located in the colony of Maryland, not Pennsylvania-which presented a problem because Philadelphia was the principal city in Pennsylvania, and the largest city in the colonies.

In the 1720s, both Pennsylvanians and Marylanders had moved into the contested region and filed claims in their respective colonies. In 1730, Thomas Cresap claimed that he was attacked by two Pennsylvanians and he felt that he was unfairly treated by the Pennsylvania court and complained to his home colony of Maryland. In 1735, Maryland sent militia into the disputed area,

Meanwhile, several Pennsylvanians accused Cresap of shady land deals. When the Lancaster County sheriff tried to arrest him, Cresap fired through the door, fatally wounding a deputy. When the Pennsylvania Governor demanded that Maryland arrest Cresap for murder, the Maryland Governor responded by appointing Cresap a captain in the Maryland militia.

With the power of his new rank, Cresap began a reign of terror on Pennsylvanians. Finally, in a wild brawling firefight, Cresap was arrested. Maryland petitioned the Ccrown to call a ceasefire, and the Crown negotiated a prisoner exchange and a new border set at 15 miles south of Philadelphia.

In 1763, to verify the exact location of the border in a relatively inaccessible area, Pennsylvania and Maryland agreed to hire astronomer Charles Mason and surveyor Jeremiah Dixon to survey the agreed upon boundaries. A continuous line of latitude was the goal, and Mason and Dixon used the stars to chart their path through the rugged terrain. Mason and Dixon were responsible for marking a 233-mile-long boundary line between Pennsylvania and Maryland and the 83-mile-long line between Maryland and Delaware.

Mason and Dixon marked their line by stones every mile and "crownstones" every five miles, using stones shipped from England. Crownstones include the two coats-of-arms. The Maryland side says (M) and the Delaware and Pennsylvania sides say (P). The exact location of the Pennsylvania/Maryland border was set at: 39°43_19.92216_ N. The process took five years and was completed in 1767.

Pennsylvania freed its slaves in 1781. Soon, abolitionists began leading the slaves across the Mason-Dixon line into freedom. The Missouri Compromise of 1820 was an agreement between the pro-slavery and antislavery factions in the United States Congress, involving primarily the regulation of slavery in the western territories, was the first time that the demarcation was called the Mason-Dixon line. When the Civil War erupted, it became the symbolic separation between the Union and the Confederacy.

But most important, the Mason Dixon line preserved Pennsylvania by creating a documented border with Maryland that kept Philadelphia in the state.