Birthplace of James Buchanan, 15th president of the United States, Franklin County was founded in 1784 and named for Benjamin Franklin. A statute of Franklin stands atop the county courthouse.
From 1729 to 1760, the area was part of Lancaster County and from 1760 to 1784 it was part of Cumberland County. With a population of about 121,000 residents, the county currently encompasses 754 square miles.
Chambersburg, the county seat, was founded in 1764 by Benjamin Chambers, for whom it was named.
Franklin County is also Civil War Country. It sustained more military activity during the Civil War than any comparable area in the North. Because of its strategic location in the heart of the Cumberland Valley, the area was the target of three major Confederate cavalry raids: Stuart 1862, Jenkin 1863, and McCausland 1864, as well as one full-scale invasion, the Gettysburg Campaign of 1863. These events incurred severe destruction and economic hardship on the population. The final visitation by McCausland's cavalry left the county seat, Chambersburg, a smoldering ruin, the only northern town burned by regular Confederate forces during the war.