Credit goes to The Windber Area Museum for posting this to their Facebook page.
Pennsylvania's counties used to look like this, at the start of the Revolutionary War in 1775.
Yep, Fayette County used to be part of Westmoreland County. It's interesting to think about how things could be different for either county had that not changed.
The museum also posted some other nice historical tidbits, like the fact that Somerset County wasn't created until 1795 and was part of Bedford County until then.