A British North America enters both world wars early

What if the United States stayed British like Canada and formed a large pro-British North American country?

Germany would face a huge pro-British country from the beginning of both world wars, with dominion status changing the path of industrialisation rather than preventing it.

A North American dominion stretching into northern Mexico would give Britain a vast ally from the opening of both world wars. Its population, resources, and growing industrial base would make Germany's position substantially worse. Remaining inside the empire would shape industrial development differently from the independent United States, while Canada and Australia show that dominions could still industrialise. British supply might initially reduce the need for a separate arms industry, though the American appetite for large guns is treated as unlikely to disappear.