The Ingersoll Tribune has a free, online index of the births, marriages and deaths that were published in that newspaper between 1897 and 1970. Ingersoll is located just East of London, Ontario and it's quite possible that former slaves from the states settled in and around the area.
Though you cannot search by keyword or use wild-card characters, it's better than nothing.
Good luck in your search.
- Lisa B. Lee, PLCGS
Oakland, CA