Mercer, PA, United States
Mercer County. Formed March 12, 1800 from Allegheny County. The U.S. census reported 3228 residents in 1800. Named for General Hugh Mercer, Revolutionary hero killed at Battle of Princeton, 1777. Early iron and coal center. Mercer, the county seat, was incorporated 1814.
Listen to the audio guide for Blue plaque № 29252 Free on WIP — starts by itself when you arrive, even with the screen off