Do you mean Captain John Montresor?
If not, feel free to re-ask giving the first name.
If you did:
John Montresor was a British military engineer. He travelled to America with his father, who was also in the military. He served in the French/Indian war and the American Revolution. He oversaw the construction of British forts and defences in the Americas and Bahamas. Some of the best forts and defences (some labelled 'impenetrable') built by the British were overseen by Captain John Montresor.
He also constructed barracks in cities such as Philadelphia and New York for the British.
In 1775 he was appointed 'Chief Engineer' in America.
Despite his hero status, he found himself in debt upon his return to Britain. The courts ordered him to be jailed in Maidstone Prison, in England, while they get to the bottom of his debt issue. He later died there during his proceedings.