Sutherland closely followed the polemics of William Lyon Mackenzie in 1837 and he knew Upper Canada lay on the verge of open rebellion. Two days before Mackenzie's botched assault on Toronto, Sutherland traveled to Toronto with a letter of support from sympathetic Americans (a trip he later denied happened).
After fleeing to Buffalo, Mackenzie spoke before a crowd of 3,000 supporters on December 11. Sutherland made certain he was on the list of speakers: he fancied himself a natural commander of men. That night, he requested men, money, ammunition and weapons to form an army of liberation. The response was immediate and generous. Mackenzie accepted Sutherland as his top general.
The next day, Sutherland demoted himself to make way for Rensselaer Van Rensselaer to become Patriot's commander-in-chief. Sutherland believed the cause needed a person better known than he to impart "a proper tone to the enterprise." Van Rensselaer accepted the role at the request of Mackenzie (he later proved to be a disastrous choice).
On December 14, Mackenzie and Van Rensselaer landed on Navy Island with 24 volunteers and two small cannons to occupy that bit of Canadian soil. As the news of the occupation spread, Canadian refugees and American volunteers from across the state flocked to Navy Island.
Joins Patriot WarBrigadier-General Sutherland brought a company of volunteers to the island December 16 but soon departed for the Patriot's western front in Ohio and Michigan. Sent by Van Rensselaer to take command, he arrived in Detroit on January 7, 1838, and found the western commanders reluctant to cede control.
After leading a rebel force on one badly bungled campaign January 10, Sutherland blamed the loss on every other leader involved. He resigned his Patriot commission on February 5, 1838, and left Detroit only to be robbed of all his belongings on his journey. He returned to Detroit and discovered the possible identity of one thief. Sutherland set out for Sandusky, Ohio, where the culprit was said to be.
While taking a short cut across Lake Erie on the ice, Sutherland may have strayed into Canadian territory. True or not, a British squad under command of Lt.-Colonel John Prince arrested him. Prince knew Sutherland's reputation and knew he'd caught a big fish.
Sutherland had the dubious honor of being the first Patriot leader changed under the Lawless Aggressions Act, proclaimed on January 12, 1838. While no trial under that act could withstand close legal scrutiny, the evidence presented at Sutherland's trial in March 1838 had no foundation. For one, Sutherland pointed out that the court martial could not legally try him under a law that didn't exist when he allegedly committed the crimes.
His arguments failed. The court sentenced him to life in a penal colony.
Aside: According to Edward Alexander Theller's memoirs, Sutherland's first response to his conviction was to attempt suicide. He slit open veins in an arm and leg. His jailor found him unconscious but alive.
The court allowed so much hearsay and unsubstantiated testimony that it gave Sutherland solid grounds for appeal once he regained his spunk. An experienced writer with a sound knowledge of law, Sutherland sent a lengthy letter to Lord Durham, Canada's Governor General, dated July 4, 1838, detailing the legal errors in the case.
Six weeks later, Lord Durham set aside the guilty verdict due to legal irregularities. Durham told Sutherland in writing that he could return to America if he posted a $4000 bond to ensure he would stay off British soil.
Sutherland then protested by letter to Lord Glenelg, secretary of state for the colonies, that he could not raise bail while in prison in a city (Quebec) where he knew no one. He questioned the flawed logic of the order, which required him to get bail in Canada and then leave never to return. What bailsmen would agree to that arrangement?
In May 1839, the British shipped Sutherland to Cornwall, Upper Canada, and released him without bail. He returned to the US and looked up his old rebel comrades, including Donald McLeod and Benjamin Lett. If he harbored dreams of new battles, they were futile. The Patriot War's military activity had passed never to be rekindled. Sutherland had missed most of the action.
By the 1850s, Sutherland was a drifter in the Midwest making a living writing and lecturing on phrenology. On September 7, 1852, he died of typhus fever in Kansas.