Imperial Scheme.

Soon after resigning the vice presidency in 1805, Aaron Burr began a journey throughout the West. Following his departure, President Thomas Jefferson received an anonymous warning that Burr was "meditating the overthrow of your Administration," "conspiring against the State," and acting as an agent of Great Britain. Other rumors of political instability in the West added to suspicions surrounding Burr's activities. Reliable sources reported that Burr was actively recruiting men for an army and officers to lead them in an effort to separate the Western territories from the United States. Combined with territories to be taken from Spain, it was alleged that Burr intended to create a new empire in the West.

The Conspiracy.

One of Burr's allies was Gen. James Wilkinson, the governor of Upper Louisiana. Wilkinson was known to be corrupt, but few at the time considered him to...