The fort was built in 1759, the location being chosen by General Abercrombie, the English Commander, as a point of defense along the all important water route and was the trail between the Great Lakes and Albany. From its location all travel up and down the Oneida River was always under observation. The site is a sloping plain on the northerly bank some 300 feet from the River’s edge, about 350 feet across the embankment. Formerly a moat surrounded it and the earthworks inside were surmounted by loophole palisades 14 feet high. About 100 feet east of the fort an underground powder magazine was connected with the fort by a tunnel.
The fort was situated on a slight elevation of land on the north side of the Onondaga (now Oneida) River and about half a mile west of the end of Oneida Lake. It was laid out in the form of a square 100 feet across, its four sides being parallel with the four cardinal points of the compass; another square 100 feet across having the same common center as the first, was laid out so that each corner of the square would point toward the cardinal points of the compass. The whole thus forming an eight pointed star with sixteen faces. The length of the parapet measured about 480 feet, and each of the sixteen faces measures about 30 feet. The wall or embankment of earth, forming the parapet was about five feet high, with loop holes and embrasures. In the interior were four block-houses of hewn timber, sufficiently large to accommodate 100 men, together with receptacles for munitions of war, provisions, etc. One or two wells supplied garrison with water. The whole was surrounded by a ditch about ten feet in depth and a covered gate way gave entrance on the Southside toward the river, from which it was distant about twenty rods. Its armament consists of four swivel three-ponder guns.
One or two wells supplied garrison with water. The whole was surrounded by a ditch about ten feet in depth and a covered gate way gave entrance on the Southside toward the river, from which it was distant about twenty rods. Its armament consists of four swivel three-ponder guns. Following the fall of Niagara, the English established a series of fortifications to secure the water route west. In the late summer and fall of 1759, they proceeded to strengthen Fort Ontario at Oswego and refurbish Fort Bradstreet at the carrying place at Fulton. Between August and October, the British built Fort Brewerton and the Royal Clock House at Sylvan Beach. These preparations prepared the English for their campaigns in the following spring. The fort was named in honor of Major George Brewerton, Jr. an estimable officer of the English Army, who is believed by many to have had charge of the construction of the fort; however as the records are silent on this point it is a matter of conjecture.
George Brewerton, for whom the fort was named, was born in the city of New York in 1737. A letter written by his father, Captain George Brewerton, Senior resulted in his commission. Mr. Brewerton was commissioned a lieutenant under his father, Capt. George Brewerton, Senior on August 1757; was commissioned Captain, May 3, 1759; Major on May 14, 1759; Lieutenant-Colonel of the 1st regiment on May 15, 1760; and Colonel in 1761.During the Revolution, he was charged with dangerous and treasonable conspiracies against the Whig cause, and the instance of Livingston, Morris and Jay, a warrant was issued in June 1776 by General Greene for his apprehension and the seizure of his paper. Brewerton surrendered himself to the general, who sent him to his accusers. In his examination, he stated that “instead of aiding the ministerial armies, I have persuaded men to enlist in the Congenital Service.” He was held to good behavior to the Whigs in a bond of five hundred pounds, with Jacob Brewerton as Security.