|In 1745 Hugh Mercer, a Scottish physician, fled Scotland after the battle of Culloden for the Pennsylvania frontier. Mercer was living in the Conococheague Settlement, now Franklin County, when war with the French and Indians broke out on 1754.
After Braddock's defeat in July 1755, attacks on the frontier increased. Mercer joined George Crogan at Augwick Creek and built a fortified post there named Fort Shirley. This post was manned by volunteers.
In February 1756 Crogan left for diplomatic duties on behalf of Pennsylvania to various tribes. Mercer was commissioned a Captain and placed in charge of Fort Shirley.
After the fall of Fort Granville in July 1756 Pennsylvania abandoned all posts west of the Susquehanna. In September 1756 Colonel Armstrong assembled an expedition to raid the hostile village of Kittanning. Mercer was chosen to lead a company during the raid. He was wounded and left behind during the attack on Kittanning, but managed to make it back to the settlements.
Mercer was promoted to Colonel and joined the Forbes expedition against Fort Dusquene. He achieved greater glory under Washington during the Revolution.