The vulnerabilities demonstrated by the Battle of Quebec in 1690 caused the Canadians to bolster defensive positions, which served their purpose until the Battle of Quebec (Battle of the Plains of Abraham) in 1759 when the British were successful in their assault. This was known by the British as part of the "Annus Mirabilis" of 1759. Two of the sons of Joseph, François and Antoine, died in this battle. Following his father's profession, Joseph entered the fur trade at its peak. By the middle half of the 18th century the fur trade was in a slow decline, and Joseph's children began migrating south to American cities such as Detroit, Chicago and St. Louis.