Final answer:
The Caroline Affair, an incident where a British force destroyed an American steamboat used by Canadian rebels, almost provoked a war with Britain in 1837.
Step-by-step explanation:
The event that almost provoked a war with Britain in 1837 was not a trade dispute, culinary competition, diplomatic success, or scientific discovery, but rather an incident known as the Caroline Affair. This episode was part of the broader context of the Canadian Rebellions and tensions between the United States and Great Britain.
The Caroline was an American steamboat used by rebels in Upper Canada and was destroyed by British forces, almost leading to a war between the two nations.