Croghan mortgaged his Otsego tract of land to William Franklin, son of Benjamin, and lost it under foreclosure in 1773. This became the home of James Fennimore Cooper, now Cooperstown, N. Y.
In the controversy between Pennsylvania and Virginia for the territory which lies west of the Laurel Hills, Croghan was a partisan of Virginia, and one of those who stirred up the most trouble.
At the beginning of the Revolution Colonel Croghan embarked in the patriot cause, being elected chairman of the Committee of Safety of Augusta County, May 16, 1775. He later became an object of suspicion.
June 15, 1778, he was declared by Pennsylvania a public enemy, and his office of Indian Agent was conferred upon Colonel George Morgan. He continued, however, to reside in Pennsylvania, and died at Passyunk, in the summer of 1782. His will is dated June 12, 1782.
Colonel Croghan married a Mohawk Indian, and their daughter, Catherine, became the third wife of Joseph Brant, the celebrated Mohawk chieftain of the Revolutionary period.
Pennsylvania Navy Meets British in Action,
May 8, 1776
The Committee of Safety, which organized July 3, 1775, early in the following year, had a survey made of the Delaware River, with a view to its more extensive fortification. Leave was obtained from New Jersey to construct works on that side of the river; a permanent fort was determined upon at Billingsport; the fort at Fort Island was hurried to completion; it was decided to fortify Liberty Island, and additions were made to the chevaux-de-frise. To the naval flotilla were added the floating battery Arnold, the ship-of-war Montgomery, the fireship Aetna and some guardboats for Philadelphia harbor. This naval force soon had a chance to show its mettle.
On May 6 news came to Philadelphia by express from Fort Penn that two warships, a schooner and three tenders were coming up the river. The Committee of Safety ordered the gunboat flotilla and the Montgomery and Aetna, under command of Commodore Andrew Caldwell and Captain James Reed, to attack the enemy. His vessels were the Roebuck, forty-eight guns, under command of Captain Hammond, and the sloop-of-war Liverpool, twenty-eight guns, under command of Captain Bellew, and their tenders.