>From Wikipedia, the free encyclopedia The Mason–Dixon line is made up of four segments corresponding to the terms of the settlement: Tangent Line, North Line, Arc Line, and 39° 43' N parallel. The most difficult task was fixing the Tangent Line, as they had to confirm the accuracy of the Transpeninsular Line mid-point and the Twelve-Mile Circle, determine the tangent point along the circle, then actually survey and monument the border. They then surveyed the North and Arc Lines. They did this work between 1763 and 1767. This actually left a small wedge of land in dispute between Delaware and Pennsylvania until 1921. In April 1765 Mason and Dixon began their survey of the more famous Maryland-Pennsylvania line. They were commissioned to run it for a distance of five degrees of longitude west from the Delaware River, fixing the western boundary of Pennsylvania (see the entry for Yohogania County). However, in October 1767 at Dunkard Creek near Mount Morris, Pennsylvania, nearly 244 miles (392 km) west of the Delaware, a group of Native Americans forced them to quit their progress. In 1784, surveyors David Rittenhouse and Andrew Ellicott and their crew completed the survey of the Mason-Dixon line to the southwest corner of Pennsylvania, five degrees from the Delaware River. Other surveyors continued west to the Ohio River. The section of the line between the southwestern corner of Pennsylvania and the river is the county line between Marshall and Wetzel counties, West Virginia. The boundary between Pennsylvania and Maryland was resurveyed in 1849, then again in 1900. Larry Kincaid 117939 A-1a Re Norman's post: From Pittsburgh, Pennsylvania >From Wikipedia, the free encyclopedia http://en.wikipedia.org/wiki/Pittsburgh,_Pennsylvania Pittsburgh was named in 1758 by General John Forbes in honor of the British statesman, Sir William Pitt. Given that Forbes was a Scotsman, some speculate the intended pronunciation of the settlement was "Pittsburra", similar to the pronunciation of Edinburgh. It was incorporated as a borough in 1794 and chartered as a city in 1816.[12] British General Edward Braddock's campaign (with Washington as his aide) to take Fort Duquesne failed, but General John Forbes's subsequent campaign succeeded. After the French abandoned and destroyed Fort Duquesne in 1758, Forbes ordered the construction of Fort Pitt, named after British Secretary of State William Pitt the Elder. He also named the settlement between the rivers "Pittsborough."[18] During Pontiac's Rebellion, Ohio Valley and Great Lakes tribes besieged Fort Pitt for two months. The siege was ended after Colonel Bouquet defeated the native forces in the Battle of Bushy Run just to the east of the forks. In the 1768 Treaty of Fort Stanwix, the descendants of William Penn purchased from the Six Nations western lands that included most of the present site of Pittsburgh. In 1769, a survey was made of the land situated between the two rivers, called the "Manor of Pittsburgh."[19] Both Virginia and Pennsylvania claimed the Pittsburgh area during colonial times and would continue to do so until 1780 when both states agreed to extend the Mason-Dixon Line westward, placing Pittsburgh in Pennsylvania. Sincerely Norman Kincaide