Westmoreland County, Pennsylvania: History
The land that became Westmoreland County was originally the home of the Iroquois (also known as the Haudenosaunee or Six Nations). The Treaty of Fort Stanwix opened up the area to colonist settlement in 1768, even though some Europeans had already arrived.
Westmoreland County was founded in 1773. It was named for Westmorland, a historic county in northwestern England. It was the first county in the colony of Pennsylvania whose entire territorial boundary was located west of the Allegheny Mountains. The county originally included the present-day counties of Fayette, Washington, Greene, and parts of Beaver, Allegheny, Indiana, and Armstrong counties.
On December 20, 1785, Joseph Ross of Westmoreland County was sentenced to death for the crime of sodomy. This is the only known execution for sodomy to take place in Pennsylvania's history.
By 1790 about 16,000 people lived in Westmoreland County (as then defined). The Whiskey Rebellion tax protest (1791-1794) took place in Westmoreland and surrounding counties.
A number of places in the county have Ulster origins, including Derry, Donegal, Rostraver, Antrim, Armagh and Tyrone, perhaps because Scotch-Irish Americans settled there.