Fort James was renamed by the British in August of 1664; it was previously known as Fort Amsterdam. It was briefly reoccupied by the Dutch as Fort Willem Hendrick in 1673 but was reoccupied the following year. Fort James was destroyed by American forces in the early years of the revolution, in 1776.
Fort Jay was built on Governor’s Island in New York Harbor in 1797. Initially serving as a battery in 1776, it was once garrisoned by the British for a number of years. The fort was upgraded in 1803 and was renamed “Fort Columbus” from 1803 to 1904, before its name was reverted back to “Fort Jay”.
The Jersey Battery was arguably among the strongest fortifications in downtown Manhattan during its time. It was located to the left of Grenadier's Battery in line with present-day Reade Street, just west of Greenwich Street. Built in 1776, the battery was a five-sided fortification with a line of entrenchments to Grenadier's Battery. In April of that year, along with the nearby Oyster Battery and Whitehall Battery, it engaged opposing British forces. After the occupation of New York, the British improved the fort’s inner workings.
Fort Jersey was built in 1776 on the Delaware River at Mohochamack Fork. It was a blockhouse, two miles from the Minisink Forts and Port Jervis. It was torn down around 1790.
Fort Johnson was built in the 1740s and served as the second fortified stone house built by Sir William Johnson. Situated on the Mohawk River, it operated as a residency during the Seven Years’ War. Today, the stone house still stands, and operates as a museum. The two-story mansion was built in an Early Georgian style with a hipped roof with three staggered dormers.
Fort Johnstown was built in the mid-1770s, in Johnstown, New York. The fortification surrounded a stone jail. The defensive structure was palisaded with blockhouses built upon diagonal corners. The fort served as a frontier jail and military prison during the American Revolution. Note from Adirondack Scenic Byways: "NYS road marker reads Third Mohawk Valley House Built By Sir William Johnson. Important Military Post and Indian Council Place of 1754 to 1760. Fort Johnstown’s heyday was between 1772 and 1776. A fortified stone jail that was palisaded with blockhouses at the diagonal corners, serving as frontier jail and military prison during the American Revolution. From downtown Johnstown and Route 30A north, turn west onto East Main Street, a.k.a. Routes 29 and 67, north onto North William Street, or Route 29, and then a right on Hall Avenue."
Joncaire's Blockhouse was constructed in 1719, in Niagara Falls, New York. The fort was known under several monikers, but most prominently known as Fort Joncaire, and Magazin Royal. Daniel Joncaire, a Frenchman who lived alongside Native Americans, built a stockaded cabin and warehouse for trading, in Lewiston at the foot of the portage, around seven miles from the future Fort Niagara. Joncaire’s Blockhouse was dedicated as Magazin Royal by the Baron de Longueuil, who served as the Lieutenant Governor of Montreal. This may have been near the site of the original 1678 French Fort Hennepin, and later, that of an unnamed storehouse in 1679. Another fort was built by Joncaire in 1750 called Fort Little Niagara or Fort du Portage above the falls (formerly the upper camp of Fort Conti in 1679).