One of Sheafe's sisters, Margaret, married Robert Livingston, of Clermont Manor, one of the Founding Fathers of the United States.

One of the residents there was Lord Percy, later the 2nd Duke of Northumberland, the leader of the British forces in Boston during the American War of Independence.

Lord Percy greatly aided the family during the War and was so struck by the qualities and the leadership potential of Sheaffe that he sent him to a military academy in London.

Lord Percy became Sheaffe's lifelong friend and benefactor, purchasing his first commission as Ensign in 1778 in the 5th Regiment of Foot.

This last promotion actually hurt Sheaffe financially, as he transferred from a full-pay commission as Colonel of the 49th to half pay as an unassigned general officer on the staff.

Brock galloped from Fort George to Queenston, arriving just in time to see the Americans capture the commanding heights and a British heavy gun battery.

In contrast to Brock's actions, he waited for reinforcements before leading his force on a wide detour to the top of the heights, so as to shield them from American artillery.

Sheaffe was appointed Lieutenant Governor and commander in Upper Canada in succession to Brock, but was unpopular with the people he was to defend, and often with his own soldiers.

During the later months of 1812 he was unable to transact business with the Legislature due to illness and other military commitments, forcing Prevost to make a personal visit to Upper Canada in February 1813.

York was weakly defended and Sheaffe had only four companies of regulars, passing through en route to Fort George and other posts.

Sheaffe decided to preserve his regulars and ordered a retreat to Kingston, having destroyed the fort and a sloop of war under construction in the dockyard.

[5] He died at his home in 36 Melville Street on 17 July 1851, and is buried in New Calton Cemetery, beside his daughters Frances Julia and Agnes Emily.

[6] In 1810, at Quebec City, Sheaffe married Margaret, daughter of Isabella Child and John Coffin (1729–1810), a relation of his mother's from Boston.