Through the late 18^th and the first half of the 19^th centuries, Prescott was a key transhipment point on the St. Lawrence River transportation system. Along the 200 kilometres between Montreal and Prescott, the river was marked by a series of extensive rapids that posed a major obstruction to vessels traveling west against the current. Because of the rapids, supplies and people destined for Upper Canada traveled to Prescott overland or on small bateaux which could be polled or manhandled up the rapids. Prescott was the eastern terminus for large lake schooners, and later steamers, traveling from Lake Ontario; here cargo was loaded aboard the larger vessels to continue journey west.

With the outbreak of war between Britain and the United States in 1812, Prescott became vulnerable to attack from the south. Its importance as a transhipment centre in the military supply line to Upper Canada was well-known to the Americans. Its location, separated from Ogdensburg, New York by less than a kilometre of water which froze into an ice bridge in the winter, left the town exposed to invasion. In the summer of 1812, the local militia occupied two buildings owned by Major Edward Jessup and erected a stockade around them.  In October, the constructed an advance battery along the river armed with two 9-pounders. In December 1812, Sir George Prevost, commander of the British forces in North America, decided to build defensive works along the river supply route, beginning with the constructions of a blockhouse – subsequently enhanced with the addition of a substantial earthworks – at  Prescott.

Harassment of the frontier towns by American troops  stationed at Ogdensburg threatened the peace of these small towns early in the war. In retaliation for a successful American raid on Brockville in February 1813, Lt. Colonel “red” George Macdonnell, the commander at Prescott, led a combined force of Glengarry Fencibles and regulars across the frozen St. Lawrence River. The destructions of the post at Ogdensburg ended the threat of an attack on Prescott by American troops based in Ogdensburg.

The construction work on Fort Wellington was completed December 1814, the same month that the Treaty of Ghent was signed, officially ending the war. At that time the fort consisted of a substantial log, one-storey, splinter-proof blockhouse enclosed by a casemated earthen redoubt plus several support buildings outside the core defensive work, including the stockade barracks to the west. In the years following the war, Fort Wellington’s garrison was gradually reduced and the blockhouse and earthworks allowed to deteriorate. The fort was finally abandoned in 1833, and eventually rebuilt during the rebellions period in 1837-38. This fort still stands today.