Invasion of Quebec
The Invasion of Quebec was a campaign by the Continental Army into Quebec Province (today known as Canada) in 1775, shortly before Independence.
During the course of the expedition, several prominent leaders were killed or injured, including General Montgomery and Benedict Arnold.
After the passage of the Quebec Act, which reorganized Canadian governance and established direct rule by the crown, leaders in the Thirteen Colonies started to become concerned that British forces could use northern territories as a military staging ground.
Preemptively pushing the British out of northern provinces would "promote peace and security" for the colonies.