When the men who attempted to kidnap Lord Gordon-Gordon to bring him to trial for swindling Jay Gould were in turn captured and imprisoned in Canada without bail, Minnesota governor Horace Austin demanded they be returned. When Canada refused, Austin ordered the Minnesota militia mobilized and put into a state of full readiness, with thousands of Minnesotans volunteering for a military expedition into Canada. Crisis was averted when Canada gave in and had the kidnappers released on bail.
What if Canada had refused to do so and the governor, or some rogue militia commander, decided to mount an invasion to free them?