Pennsylvania Census and County Formation Maps

I'm not from Pennsylvania.

I've never been to Pennsylvania.

Imagine how puzzled I look when I see that somebody was born in maybe Northampton County, then moved to Bedford County before part of it became Westmoreland County... and I have no idea when any of this happened.

This helps:
An animated map of the formation of the counties of Pennsylvania.
CLICK HERE

Click on "Play" to watch PA grow, or click on any of the listed years to see how the state looked at any given time.