Short answer - following the battle of the Plains of Abraham in Quebec, in 1759, where the British forces under Wolfe beat the French under Montcalm, the British gained control of what was later to become Canada. The British required the French/Quebecois to swear an oath of allegiance to the King at the time but otherwise left the residents alone with freedom of religion along with language. Essentially the motivations that led to American revolution didn't exist in the same way.

There were many more complexities to the situation and I'm certain that someone can provide a more nuanced answer - I'm Canadian and relying basic high school history that we all learn along with a field trip to the Plains of Abraham.

Late answer but...

Sometimes many Americans lose sight of the fact that in 1776 there were 19 British colonies in North America. Thirteen of which openly rebelled. These 13 colonies were also hotly contested between loyalists and rebels. There were many loyalist strongholds up until the Treaty of Paris (including New York and many areas of the Appalachian south).

Nova Scotia and St Jean (Prince Edward Island) were very young English colonies acquired after Queen Anne’s War. They weren’t connected to the 13 colonies by road, and there was a major Royal Navy presence in The region. There was also a pacifist religious revival called the Great Awakening that Gained popularity in the region the year before the war of independence.

“Canada” (today what we refer to as Ontario and Quebec) was an almost exclusively French colony before the 1780s. The Canadiens were weary of the American colonials who cited the Quebec Act as one of the Intolerable Acts. The Quebec Act was very generous to the Canadiens and the Roman Catholic order in the region. The rebels never offered any guarantees towards securing traditional land tenureship and religious order that was very important to the inhabitants.

Still, the American colonials led by Benedict Arnold and Horacio Gates did raise two Canadian regiments who fought for the rebels, and they were very active throughout the war. Most notably in the Battle of Saratoga.

Newfoundland was too far away, separated by sea, and was little more than a fishery in the 1770s. The new American government did negotiate fishing rights. Newfoundland has always been more connected to the “Old World” than the New during an era where sail was the most expeditious form of transportation. It didn’t even become a Canadian province until 1949.