The new French Revolutionary government declared war on Britain on 21 January 1793. The new republic of the United States was sympathetic to the new French regime. As a consequence, the British took steps to upgrade the defences of Halifax harbour. British troops built Fort Duncan and Fort Olgivie to protect the naval shipyards in Dartmouth.
The following year the commander-in-chief at Halifax, Prince Edward, Duke of Kent, proposed the construction of a stone fortification to replace the earthworks and wooden palisade. A British army engineer, Captain Straton, supervised the building of the Halifax citadel in 1795. The new fort could accommodate 1,000 troops, 1,200 barrels of gunpowder, and provisions for three months.
Between 1796 and 1798, the British troops constructed three fortified towers to augment the harbour's defences. By 1799, Halifax was a formidable military and naval base.