Colonel Patrick Mackellar (1717 – 1778) was a British army officer and military engineer who played a significant role in the early history of North America.
The British surrendered during the afternoon of 14 August and Mackellar, having survived the subsequent massacre perpetrated by Montcalm's native allies, was taken to Quebec City where he was kept closely guarded.
On 4 January 1758, Mackellar was promoted to major and sub-director of engineers and was appointed deputy to Colonel John Henry Bastide in the expedition against Louisbourg, the key to control of the St Lawrence River, the vital supply line of Canada.
Although Wolfe was impatient with the slow progress of the siege (and let his unflattering opinion of military engineers be generally known), it appears that not a little of the credit for the capitulation of Louisbourg on 27 July was due to Mackellar's professional skill.
[2] Mackellar was with Wolfe during the famous scaling of the cliffs on the night of 12/13 September and, immediately after the victory at the Battle of the Plains of Abraham, he prepared to extend the siege operations against the newly exposed walls of the upper city, but the capitulation of Quebec five days later made these efforts unnecessary.
During the autumn of 1759 and the spring of 1760, he strengthened the defences of the city against an expected French counterattack, and had the direction of the artillery in the force under Brigadier-General James Murray at the Battle of Sainte-Foy on 28 April.
Although critically wounded in the battle and subsequent withdrawal through Sillery to Quebec, Mackellar supervised the defence of the city during his convalescence and up until the arrival of a British squadron in May forced the French to raise the siege.
In November 1760, Mackellar was appointed chief engineer at Halifax, Nova Scotia, where he initiated important works to improve the defences and devoted much time and energy to training troops for siege operations.
On 7 June, the troops landed in Cuba and began the campaign by besieging the fort of El Morro that was strategically sited at the harbour entrance opposite the city of Havana.
In desperately hot conditions and ravaged by disease, the British forces made slow progress, but on 30 July two mines were exploded, caving in the huge ditch protecting the landward side of El Morro.
He rose to the rank of admiral of the blue, despite being court-martialed and dismissed the service in 1802, and served in Halifax from 1804 to 1810 as agent for prisoners of war and transports and as governor of the naval hospital.
This settlement had sprung up around the fortress in response to the lack of quartering for soldiers within the fort itself and in the inevitable way that taverns, sutlers, families and less reputable women coalesced around the armies of that time.
"A sketch of the field of Battle of July 9th upon the Monongahela seven miles from Fort Du Quesne, showing the Disposition of the Troops when the Action began" is considered the best map detailing events during Braddock's defeat.