Butler County was formed by an act of the Assembly of Pennsylvania on March 12, 1800, by severing a portion of land from Allegheny County.

When the county was founded, it had a population of 3,916.

The county had four townships at the time: Connoquenessing, Buffalo, Middlesex and Slippery Rock. Now it has 33 townships.

Gen. Richard Butler was the county’s namesake, although he never actually visited what is now Butler County.

Butler, who was born April 1, 1743, in Carlisle, Cumberland County, fought in the Revolutionary War and was killed in action in 1791 by the Miami (Ohio) Indians.

Some historical publications say Butler was born in Northern Ireland and his parents later migrated to Pennsylvania.

By another act of the Assembly on April 2, 1803, the county was organized for judicial purposes.

As part of the original founding in 1800, the seat of justice was to be not more than four miles from the center of the county.

So in 1803, the formation of 502,400 acres which comprise Butler County were completed. Of this land, 300 acres were laid out for the borough of Butler, the county seat. Today, Butler is a city.

In March 1803, the legislature passed another act that appointed John McBride, William Elliot and John David as trustees for the county and gave them the power to lay out the county seat.

Butler County’s first commissioners were Matthew White, James Bovard and Jacob Mechling. They became commissioners in 1803.

By 1820 the county’s population had grown to 10,193.

The borough of Butler had at least six taverns, a blacksmith shop, quarries, a grist mill, the Butler Academy, a Presbyterian church and a courthouse, which opened in 1807, according to “Concise History of Butler County Pennsylvania 1800-1950,” written by J. Campbell Brandon in 1962.

The county’s first courthouse was built in 1803. The second was built in 1853, remodeled in 1877 and destroyed by fire in 1883.

The current courthouse was built in 1885-86 and improved in 1907.