Henry Caldwell fought with distinction at the capture of Louisbourg, Cape Breton, afterward promoted to captain by James Wolfe (who included him in his will) and assistant quartermaster to General Guy Carleton, 1st Baron Dorchester during the Siege of Quebec.
Described as 'a handsome soldier', Caldwell was supposed to be the inspiration for the character Colonel Ed Rivers in the novel The History of Emily Montague, by Frances Brooke.
From the mills he built he supplied the troops stationed in North America and bought boats, wharves and warehouses to produce, store and export his goods.
In 1804, as a result of the Napoleon's European blockade, Caldwell persuaded Henry Dundas, 1st Viscount Melville, the Lord of the Admiralty, to instead develop Canadian timber for the Royal Navy [citation needed].
Long after his death, in 1823, it was discovered that he had embezzled nearly £40,000 during the exercise of his duties, including almost £8,000 from the Jesuit estates, which he had managed as treasurer of the commission set up to administer them.