The county of Westmoreland was erected by the Assembly of the Province of Pennsylvania by an act of February 26, 1773. It was the eleventh county in Pennsylvania and the last erected under the Proprietary Government. Like all the other counties, except Philadelphia, it received its name from a county in England. In 1771 this wide region was included in the county of Bedford, but settlements grew so rapidly west of the mountains during the year 1772 that a new frontier county was demanded. The evacuation of Fort Pitt by the British troops in the fall of 1772 also led the frontiersmen to demand a stronger civil government. When Westmoreland was erected it included all the Province west of Laurel Hill, being what is broadly known as Southwestern Pennsylvania and included what is now Westmoreland, Fayette, Washington, Greene, and the parts of Allegheny and Beaver Counties south of the Ohio River and about two-thirds of Indiana and one-third of Armstrong County, a total area of 4,700 square miles. While this was the area of Westmoreland County in the intent of the Provincial Government, it was restricted in fact by Virginia’s seizure and government of a large portion of the territory. A general settlement of the country west of the Allegheny Mountains did not begin until after the land office was opened in April, 1769. The settlers flocked into this new region from two directions. The Scots from the Cumberland Valley and other settled posts of the Province made their way westward along the Forbes military road and planted their cabins along its course. These men were loyal Pennsylvanians, and they held their lands under the Provincial Government. Other Scots came from the South, principally from the Old Dominion; they crossed the mountains by the Braddock road and occupied the fertile lands along the Monongahela and Youghiogheny Rivers and Chartiers Creek. These men were Virginians and believed their settlements were still within that territory. A lively contest was carried on between Pennsylvania and Virginia for control of this region, and the organization of Westmoreland County had signal influence in strengthening the Pennsylvania authority, especially when sixteen magistrates were commissioned to administer justice within its boundaries. The county seat was established at Robert Hanna’s little settlement on Forbes Road, about thirty-five miles east of Fort Pitt, and here at Hannastown, the first Pennsylvania court, west of the mountains, was held April 13, 1773. It was a Court of Quarter Sessions and William Crawford presided. These proceedings stirred up the Virginia authorities. The Earl of Dunmore, Governor of Virginia, took forcible possession of the disputed territory. He appointed John Connolly, of Pittsburgh, “captain commandant of Pittsburgh and its dependencies.”