Welcome, P.O.G.!
Yes, traditionally, apple pie is considered as "American" as it gets. And yes, other pies are typically associated with various regions of the U.S.
For example:
Shoo-fly pie around the Pennsylvania area.
Key lime pie in Florida
Georgia Peach pie
Pecan pie and sweet potato pie the South
Blueberry pie - Maine
Pumpkin pie, pretty much everywhere, around Thanksgiving
In addition, New York is famous for cheesecake, and Boston has its Indian Pudding (which many people think is an acquired taste, LOL!)
Looking forward to hearing other suggestions, too!
Lee