Reading Robert Bothwell’s Your Country, My Country, I was interested to learn about the Republic of Canada and the SS Caroline, historical details that had previously escaped me. In 1837, Upper Canada (that is, present-day Ontario) was rocked by a rebellion, led by William Lyon Mackenzie and directed against the so-called Family Compact that ran the place. Upper Canada had been set up in conservative reaction to the United States, and so had an established church and a government that was not actually responsible to its people. One did not need to be American to object to this situation, thus Mackenzie’s rebellion; it was unsuccessful, but an inquiry by Lord Durham recommended certain changes to the political situation to forestall future incidents, among them the union of Upper and Lower Canada into a single entity.

(When I first learned about this in grade eight, at my public junior high school, it was pretty clear that Mackenzie was supposed to be the good guy. What a surprise the next year when, playing sports for my private high school against Upper Canada College, I discovered a monument to its cadet corps, which had valiantly helped to defeat the rebels in the Battle of Montgomery’s Tavern. This was one of the many signs that I was now living in a different world.)

Mackenzie, defeated in Toronto, retreated with his men to Navy Island in the Niagara River where they proclaimed an independent “Republic of Canada” and where they were supplied from the American side by sympathizers who sent money, food, and arms to them on the steamboat Caroline. On December 29, 1837, however, Col. Allan MacNab (who was later the premier of the united province of Canada) led a party of militia across the international boundary, seized the Caroline, chased off its crew, set it on fire, and sent it over Niagara Falls! From Wikipedia, here is a depiction of the event by George Tattersall:

This was an international incident. President Martin Van Buren protested strongly to London, and in retaliation the next year a group captured and burned the British steamer Sir Robert Peel while in U.S. waters. But the Caroline incident has had a lasting influence: it has been invoked many times since in the justification of “anticipatory self-defense” a.k.a. the preemptive strike, like the one that the United States launched against Iraq in 2003.