In 1745 a small blockhouse and storehouse were built at "Frenchman's Landing". In 1751 the upper end of the portage was moved and Daniel Joncaire, son of Louis, first built Fort Little Niagara, also known as Fort du Portage. It was a log stockade around barracks, storehouses, stables and a blockhouse. The French destroyed it to prevent capture by the British in 1759. All that remained was the barrack's chimney. The chimney was incorporated into the British fort's mess hall. The British rebuilt the fort as a square earthwork with four bastions slightly upstream from the French fort site. This fort was named for it's first commander, Captain Schlosser. The fort was the departure point of Bradstreet's expedition during Pontiac's Rebellion in 1764.
Although the Americans won the land with the Treaty of Paris in 1783, they did not actually get custody of the fort until the Jay Treaty in 1796. Once they took custody, it was used mainly as a supply depot. The British attacked the fort in Jul 1813 as part of the War of 1812. In Dec that year, they burned the fort.
It may have been rebuilt and used as a supply depot until 1857, as some reports say that it burned in 1857. All that remains is the old chimney. The chimney has been moved and it is located near the intersection of Buffalo Ave and Robert Moses Parkway off-ramp. A NY State marker is located there as well.