The petition of Peter Martin, a Free Negro,... and his brother Richard Martin served in Col. Butler's rangers...four years and a half....discharged at the peace of 1783...soon after which Richard died, leaving a family...that your petitioner has received the military lands
20 August 1797
Also as an abstract here.
From this site:
Upper Canada's African-Canadian population was a mixture of free veterans who were granted land for their military services and a larger number of slaves who were without rights and freedom. The initiative taken to change this [slavery] came from an African-Canadian named Peter Martin.