John Graves Simcoe, Lieutenant Governor of the colony of Upper Canada, the colonial division of British North America that will eventually become Ontario, had been a supporter of abolition before coming to Upper Canada; as a British Member of Parliament, he had described slavery as an offense against Christianity.
By 1792 the slave population in Upper Canada was not large.
However, when compared with the number of free settlers, the number was not insignificant.
In York (the present-day city of Toronto) there are fifteen African-Canadians living, while in Quebec some one thousand slaves can be found.
Furthermore, by the time the Act Against Slavery will be ratified, the number of slaves residing in Upper Canada will have been been significantly increased by the arrival of Loyalists refugees from the south who bring with them servants and slaves.
At the inaugural meeting of the Executive Council of Upper Canada in March 1793, Simcoe hears from a witness the story of Chloe Cooley, a female slave who had been violently removed from Canada for sale in the United States.
Simcoe's desire to abolish slavery in Upper Canada is resisted by members of the Legislative Assembly who own slaves, and therefore the resulting act is a compromise.
The bulk of the text is due to John White, the Attorney General of the day.
Of the sixteen members of the assembly, at least six own slaves.
The law, titled An Act to Prevent the further Introduction of Slaves and to limit the Term of Contracts for Servitude within this Province, states that while all slaves in the province will remain enslaved until death, no new slaves can be brought into Upper Canada, and children born to female slaves after passage of the act will be freed at the age of twenty-five.