Colby Cosh linked to this Ottawa Citizen article by Andrew King:
Mapped out with defensive moats, trenches and cannon placements, Bytown’s sprawling stone fortification on the hill was a typical 19th century “star fort,” similar to Fort George in Halifax, also known as Citadel Hill, and the Citadelle de Québec in Quebec City. The “star fort” layout style evolved during the era of gunpowder and cannons and was perfected by Sebastien Le Prestre de Vauban, a French engineer who studied 16th century forts designed by the Knights of Malta. A star fort built by the order with trenches and angled walls withstood a month-long siege by the Ottoman Empire. This layout remained the standard in fort design until the 20th century.
Ottawa’s planned fortress would have also integrated a water-filled moat trench to the south, where Laurier Street is now, to impede an attack. On the northern side, the natural limestone cliffs along the Ottawa River would have served as a defensive measure. Access and resupply points were at the canal near the Sappers Bridge, and a zigzagging trench with six-metre-high stone walls would have run parallel to Queen Street. Parliament Hill, with its gently sloping banks to the south, was called a “glacis” positioned in front of the main trench so that the walls were almost totally hidden from horizontal artillery attack, preventing point-blank enemy fire.
Conceptual image by Andrew King of the “alternate reality” where Fortress Ottawa came to be.
After the rebellions were quashed and the threat of an attack from the United States fizzled out by the mid-1850s, Canada abandoned plans to fortify Bytown.
In 1856, the Rideau Canal system was relinquished to civilian control, and three years later Bytown was selected as the capital of the Province of Canada. The grand plans for Ottawa’s massive stone fortress were shelved and the area that would have been Citadel Hill became the scene of a different kind of battle, that of politics.
