Fort Bosley was situated in the forks of the Chillisquaqua, at Washingtonville, Derry Township, Montour County, and was the gristmill of a Mr. Bosley, who moved here from Maryland a few years before the Revolution, bringing his slaves with him. He built the mill, it is said, in 1773; it is supposed he fortified (stockaded) the mill in 1777; upon the Indians becoming troublesome it was garrisoned by troops and recognized by the military authorities as of importance. After the fall of Fort Freeland it became more’ so, holding the forks of the Chillisquaqua and defending the stream below it.
The Chillisquaque Valley and its surroundings are among the most beautiful in the State. At Washingtonville, the main stream is formed by one considerable branch coming from the Muncy Hills, following through the rich lime stone lands to the south. The east branch here joins it, making a fine stream that then flows southwesterly to the river. This great scope of fine arable lands attracted settlers early, Bosley’s Mills became a necessity, and, situated as it was, within the forks about sixty to eighty rods above the junction of the branches, on the east bank of the North Branch of these streams. It soon became widely known; roads and paths led to it as a central point, and on the Indians becoming troublesome and the mill fortified, it became a haven of refuge at which the wives and families could be placed in safety at alarms, while the husband and father scouted for intelligence of the foe or defended the fort. As Bosley’s Mills do not appear to have had a heavy garrison of troops (twenty men at most) at any time, the garrison was most probably augmented by the near set tiers, of which there was quite a number. It must have been strong, as we have no account of any attack on the place, lying as it does below the great war path through or over the Muncy Hills, it must have been looked upon by the foe as strong.
Col. Hunter to Prest. Reed dated Fort Augusta, June 26, 1779, says: “Your favor of ye 2d Inst. I received by Mr. Martin and I am sorry to acquaint you it was not in my power to send any of the Ranging Company to assist at Guarding the stores up here from Estherton, as what few men Capt. Kemplon had under his command was stationed at Bosley’s Mills on Chilisquaqua.” (See Pennsylvania Archives, vol. vii, p. 510.)
Lieut. Col. Weltner to Board of War dated Northumberland. April 9, 1780, says: “I have this moment received an express from the West branch, about 12 miles from this Town that the Indians have killed and scalped one man and two children, took one woman prisoner, but she happily made her escape from them in the night. The country is very much alarmed, and likely to go to the flight as they cannot be supplied with provisions, ammunition or flints, as these commodities being so very scarce. I have manned three material outposts, viz: Fort Jenkins, Fort Montgomery and Bosley’s Mills. It is out of my power to scatter my men any more, as I have scarcely as many in Town as will man 2 pieces of artillery.”
The site of the old mill is recognized readily by the race and mill site and is on the land of Jesse Umstead, Jr., at the lower end of the built up town of today. The headrace has been continued on across the road and utilizes the old dam site and head race for a modern mill.