It was one of several islands in the area that were named by John Graves Simcoe after General James Wolfe's adjutants in the Battle of the Plains of Abraham.

During the American Revolutionary War the British used the island as a military supply transshipment location, naval station, and for building ships.

After the fall of New France at the end of the Seven Years' War, maintaining inland water routes in the Great Lakes for the purpose of commerce and transportation was important to the British.

With the outbreak of rebellion against the British which led to the American Revolutionary War, it became especially important to secure supply lines and military supremacy on Lake Ontario.

The island became a transshipment point for supplies, became the main base for British ships on Lake Ontario, and the construction of a fort was started (but never completed).

It was built on the southwest end of the island, shaped as a partial octagon, and consisted of bastions, ditches, barracks and magazines.

When the island was ceded to the United States after the Revolutionary War, many of these civilian residents moved to nearby Cataraqui (now Kingston, Ontario).

[21] After contentious negotiations, the island was retained by the United States and was turned over to peaceful pursuits of farming (now abandoned), sport-fishing, and summer tourism.

Designed by William Henry Miller, the 15,000-square-foot (1,400 m2), 11-bedroom Richardsonian Romanesque-Tudor Revival hybrid mansion was occupied briefly as Wyckoff died a day after moving into it in 1895.

[1] The property was briefly held by General Electric, which had intended to transform it into a corporate retreat; however, these plans were abandoned during World War II.

The mansion is crumbling; removal of windows and doors during World War II left it open to the elements and both the stone foundation and the wooden upper floors have deteriorated.

[1] A pair of silos on one property on the southeast side of have been converted to private residences that double as observation towers.