Names of Those Convicted of High Treason During War of 1812

During the War of 1812,  most of the inhabitants of Upper Canada (present day Ontario) fought on the British side in defence of the colony. Some did their best to stay neutral but some preferred the American side and openly joined the invaders in the fighting.

Civil Secretary's Correspondence, Upper Canada Sundries
May-August 1815, No. 5, A1, Vol. 23

In November and December of 1813 the Canadian militia surprised a group of invaders near Chatham, Ontario. Among the prisoners were 15 residents of Upper Canada. They were sent to York to be tried in the court. Court proceedings began in Ancaster on 23 May 1814. Nineteen men were officially charged with High Treason. In June, the following men were found guity of treason:

Jacob Overholtzer, Aaron Stevens, Garrett Neill, John Johnston, Samuel and Stephen Hartwell, Dayton Lindsey, George Peacock Jr., Isaiah Brink, Benjamin Simmons, Adam Crysler, Isaac Petit, Cornelius Howey, John Dunham, and Noah Payne Hopkinsy. Dayton Lindsey.

Noah Payne Hopkins, John Dunham, Aaron Stevens, Benjamin Simmons, George Peacock Jr., Isaiah Brink and Adam Crysler were executed by hanging on 20 July 1814 at Burlington Heights.

Letter 28 July 1815 Informing Officials of the Deaths

Garrett Neill, Isaac Pettit and Jacob Overholtzer were sent to Kingston Gaol where they remained under sentence of death or transportation for the crime of High Treason. 

Their deaths in prison were reported in 1815 as Garrett Neil on March 6, 1815, Jacob Overholtzer on March 14, 1815 and Isaac Pettit on April 16, 1815 

We learn more details of these men in Vol. XII - Ontario Historical Society, (1923) THE ANCASTER "BLOODY ASSIZE" OF 1814. BY THE HONOURABLE WILLIAM RENWICK RIDDELL, LL.D., F.R.S.C., ETC. Justice of the Supreme Court of Ontario, 1923

Friday, June 17, Issac Petit (Pettit) was placed in the dock before the
Chief Justice. It was made to appear from the evidence that Petit had taken some part with the marauders, but he had refused to accompany them and had been branded as a coward; the case, however, was clear, and he was justly found guilty.

Petitions had already begun to pour in. Jacob Overholzer was described as "an unfortunate but honest old man" by many loyal inhabitants of the Township of Bertie as early as June 11. The Executive Council conferred with the Judges and the Attorney General, and after anxious consideration and careful weighing of all the facts, it was determined that seven might be saved from death; these seven, the Hartwells, Cornelius Howey, Issac Pitt[sic - Petit], Jacob Overholzer, Garret Neill and John Johnson were
respited till July 28, to enable proper enquiry to be made and proper terms fixed for commutation. 

The Chief Justice refusd to advise whom to execute but he recommeded that as the convicted men were all from the Niagara and London Districts, one at least from each District should be executed; at the same time he pointed out that the President had no power to pardon for Treason

In the latter part of the winter there broke out in Kingston Gaol, the dreaded Jail-fever which, under that name, or that of ship-fever, spotted-fever, etc., was the scourge of crowded gaols, ships and other confined places. It was a virulent type of typhus fever, then and for long  after believed to be "generated out of filth and overcrowding, bad diet and close, foul air", but now known to be due to the activity of the busy "cootie", as malaria to the mosquito, and the plague to the rat-flea.

Some of the unhappy prisoners were seized with the disease, and three died of it, Garrett Neill, March 6, Jacob Overholzer, March 14, and Isaac Petit, March 16, 1815.