Today in 1825, eastern Ohio and western PA seem to have been struck by supercells. The Ravenna Courier of Portage County, Ohio mentions hail-stones of 7 to 8 inches in circumference. "In some places," the report goes on, "The hail was attended by a heavy gale of wind" - enough to "literally destroy" one barn, which was broken down into "fragments" - all of this was thrown half a mile by the wind.
Farther to the east, the Chambersburg, PA paper reported complete destruction of whole fields of rye - in 1825, rye was a SIGNIFICANT crop in PA, the nation's leading distiller state until Prohibition. 10 to 20,000 panes of glass were thought to have been broken in Chambersburg proper, and the cloud's breadth was estimated at 2 miles.
Mill-dams were destroyed back to the west in Washington County, PA.
Of greater interest to me is that Tornado Archive reports a large and violent tornado in Butler County, PA: " A very violent tornado touched down in the southwestern section of Butler County, passing toward the northeast, passing 6 miles from Butler. It was a mile wide and appeared as 'a huge volume of smoke, arising from a tremendous fire.' It passed within six miles of the town of Butler, leveling everything before it to the ground, including houses, barns, orchards, and woods."
This would certainly be among the largest and most intense tornadoes in Pennsylvania history, but I am unable to find the source or others like it. Bear in mind that while western PA was pretty well settled by 1825, this is still 1825...if there was a newspaper in Butler then, and I'm sure there was, I can't seem to find one. I did email the Butler Historical Society to ask if they have any information.