Battle of the Windmill The Battle of the Windmill was a battle fought in November 1838 in the aftermath of the Upper Canada Rebellion . Loyalist forces of the Upper Canadian government defeated an invasion attempt by Hunter Patriot insurgents based in the United States . Background . After the first rebellion by disaffected Upper Canadians was suppressed in 1837 , the majority of the rebel leaders fled to the United States . Popular sentiment in the States believed that the Canadians were eager to overthrow British rule and form a republic patterned after the American model , and an organization known as the Hunter Patriots was formed to assist the rebellion . Organized in neo - Masonic secret lodges , and with widespread support in the northern border states from Vermont to Wisconsin , the Patriot Hunters aimed to invade Canada and lead an army of insurgent Canadians against the British colonial government . In reality , much of the Canadian population was loyal to existing British institutions and decidedly against the prospects of revolution or invasion . In November 1838 , a group of Hunter Patriots decided that it was time to invade Canada and restart the rebellion . They chose as their target the town of Prescott , on the north bank of the St . Lawrence River downriver from Kingston . Prescott is the site of Fort Wellington , a British military fortification which commanded the St . Lawrence River and which was serving as a fortified depot for the Upper Canadian militia . To initiate the strike , a large group of Hunters assembled in Sackets Harbor , New York and descended the River to Ogdensburg in civilian vessels . Overall military command of the insurgent forces was held by John Birge , a senior member of the Hunter organization in New York state . Attempted seizure of Prescott . Early in the morning of November 12 , a force of about 250 men attempted to land in Prescott . However , the British had infiltrated the Hunter organization , and had advance warning of the attack . With the element of surprise gone , and with the town militia ready to repel a landing , the Hunter forces were forced to abandon the landing . Both vessels ran aground on a mud flat where the Oswegatchie River flows into the St . Lawrence off Ogdensburg . Later in the morning , Bill Johnston , Admiral of the Hunter navy , arrived and succeeded in freeing the stranded vessels , which ran downriver to Windmill Point , a promontory located approximately two miles east of Prescott . Here , most of the Hunter forces landed to occupy the hamlet of Newport and its most prominent feature , a large , stone windmill building which enjoyed a panoramic view of the St . Lawrence River as far west as Brockville and eastwards over the Gallop Rapids . The commanders of the Hunters appointed a Swedish immigrant with some military experience , Nils von Schoultz , to command the Hunter forces while the Hunter leadership withdrew to Ogdensburg to collect reinforcements and supplies . First assault . The windmill was built of thick stone and stood high on top of a bluff . Although the structure had not been intended to play a role in the invasion , it was an ideal field fortification . Its height would prevent the British forces from approaching unobserved , and its thick stone walls were impervious to small arms and to small field and naval artillery . Early on the morning of 13 November , a force under the command of the militia officers Colonel Plomer Young , Colonel Richard Fraser , and Colonel Ogle Gowan and comprising a handful of British infantry from the 83rd Regiment and approximately 600 Canadian militiamen invested the Hunter position around Newport . Their attack failed , leaving 13 regulars and militiamen killed along with 70 wounded . Approximately 18 Hunters were also killed along with an unknown number of wounded . The next several days were a standoff . As time passed , von Schoultz ' s position had become desperate . Promised reinforcements and supplies never arrived as the United States Navy aided the Royal Navy in blocking egress from Ogdensburg . Law enforcement and military officials in Ogdensburg secured all of the available vessels , and most of the prominent Hunter leaders fled from town to avoid arrest . Second assault . With the arrival of heavy artillery from Kingston as well as sizeable detachments of British regulars and Canadian militia , the final attack began with an artillery bombardment of the windmill on November 16 . With Royal Navy gunboats and steamers blocking the Hunters from escaping and casualties mounting , von Schoultz decided to unconditionally surrender . Aftermath . In the aftermath of the battle , almost all of the Hunters were captured and were transported to Kingston for trial . Eleven people , including the Hunter leader Nils von Schoultz , were executed ; another 60 were sentenced to transportation to Australia . 40 were acquitted , and another 86 were later pardoned and released . Von Schoultz enjoyed the legal counsel of John A . Macdonald , a prominent young Kingston lawyer who would later become the architect of Canada ' s Confederation in 1867 and the nation ' s first Prime Minister . The site of the battle was designated a National Historic Site of Canada in 1920 .