I was reading a book about the ARW recently that focused on the war in the northern colonies and the role people and events in Nova Scotia played not only in that phase of the war, but the overall course of the war; Legge's crackdown on dissident speech and public assembly, Johnathan Eddy, the Arnold-Stark Expedition, the 'Sabotage War' in Halifax and Yarmouth, the Nova Scotia privateers (a crucial factor- and faction -in the formation of the United States Navy), etc..., and I can't help but wonder if the colonies could have succeeded without such a crucial member of the coalition.
What if the Arnold-Stark Expedition had actually attempted it's original plan: Travel up the Kennebec Track, cross the height of land to Lake Mégantic, then make the descent to Quebec via the Chaudière River?
Aside from the overly ambitious route to the city (which was much more fortress than city), what the hell were they supposed to do once they got there? Even if Montgomery's force captures Montreal (the other prong of the invasion), they're facing one of the most formidable fortresses in the western hemisphere- without a single heavy siege gun!
Far smarter to do what they did; sail straight from Cambridge to the Bay of Fundy, make landfall on the north shore and strike inland, taking the small forts in Cumberland and Sunbury Counties. That campaign convinced (most) Nova Scotians the rebellion was credible. What would getting clobbered in Quebec have done?
Without the contributions of the men and women of Halifax and Yarmouth to the overall war effort (both on the high seas as privateers and in the ports as saboteurs and spies) I can't help but think that the war would have been an even steeper uphill battle, or perhaps even a failure.
What would U.S. history look like without Nova Scotia's contributions?
What would Canada's history look like if Nova Scotia had stayed loyal?
I figure, if Nova Scotia had stayed loyal, it probably would have become a prime dumping ground for all those loyalists that were sent to present day Ontario in OTL. Ontario's importance to helping Canada form a national identity cannot be denied. Without such a large, loyal (and well armed) population in the former Upper Canada, it might have been a tempting target for invasion in 1812. I'm not so sure going on the offensive would have been a good idea in 1812; not on land at least.