Major General Edward Braddock's ill-fated 1755 military expedition to dislodge the French and their Indian allies at Fort Duquesne established a major transportation artery, Braddock's Road, into Western Pennsylvania. This military road, from Virginia through Cumberland, Maryland, had a major impact on the future settlement of the region - providing easy access to Western Pennsylvania for immigrants from Maryland, Virginia and the western Carolinas. It was not until Brigadier General John Forbes built a military road from Carlisle to present-day Pittsburgh in 1758, that the door was opened for settlers from eastern Pennsylvania to start settlements in what is now Westmoreland County. The Forbes Road, or the "Great Road" as it was known to the thousands of settlers to follow, entered present-day Westmoreland County at the top of the Laurel Ridge near where a fort was constructed. It was named Fort Ligonier by General Forbes in honor of Sir John Viscount Ligonier, Commander-in-Chief of all of the kings forces. By the fall of 1758, Fort Ligonier was the military springboard for the assault on Fort Duquesne that drove the French from western Pennsylvania.
The Forbes Road continued from Ligonier through present-day Youngstown, Hanna's Town and Murrysville and on to the forks of the Monongahela, Allegheny and Ohio Rivers where General Forbes would rename the captured French fort, "Pittsbourgh" in honor of the British Prime Minister William Pitt. By eighteenth century frontier standards, the Forbes Road provided a "superhighway" into the western Pennsylvania wilderness.
The duel for North America between England and France known to the Americans as the French and Indian War, ended in victory for the British in 1763. The Battle of Bushy Run, near present-day Harrison City, was the site of a pivotal battle in that war. On August 5th and 6th, 1763, British troops under the command of Col. Henry Bouquet, met and defeated a large Indian force at Bushy Run, effectively ending a major threat to the safety of the settlers in the region.
The end of the French and Indian War resulted in the British government issuing the Royal Proclamation of 1763. Issued to placate the Native American tribes who were complaining about the encroachment of white settlers on their lands, the act forbade English settlement beyond the head waters draining into the Atlantic Ocean from the Crest of Laurel Hill. Neither the threats of arrest nor later enactment of a death penalty for violators of the law stopped squatters and some early traders from moving into the area. The Treaty of Fort Stanwix with the Six Nations, Delaware and Shawnee Indians in 1768 finally permitted settlement west of the Alleghenies. Fueled by glowing accounts of the land to the west, taken back east by the soldiers of Braddock and Bouquet's armies, settlers poured into western Pennsylvania in pursuit of land.
As the area of Westmoreland County began to be settled, the composition of the population began to take shape. In the main they were the landless, the disinherited and the defranchised. They were bold, aggressive, hardy, courageous and self-reliant. They were churched and unchurched. They often had little respect for authority or title. Having experienced arbitrary and capricious government in England, they were zealous defenders of personal liberty and self-government. Ethnically, the majority of the population in early Westmoreland was composed of Scotch-Irish, German and English settlers. They were predominantly Presbyterian and Lutheran.
The Penn goverment soon found it necessary to create a new county, both to establish the province's ownership of the land and to establish law and order in an area, where many unruly individuals cared little about civil law or the laws concerning land ownership. Bedford County, established in 1771, had assumed superficial jurisdiction over settlements in western Pennsylvania in addition to administering to the populations along the eastern slopes of the Alleghenies.