2. A former vice-president was tried for treason in 1807
Aaron Burr was the Vice-President of the United States when he fought his famous duel with Alexander Hamilton, which damaged his political career beyond measure, though he avoided prosecution. Burr, while still serving as vice-president in 1804, contacted British Minister to the United States Anthony Merry, informing him that the residents of recently purchased Louisiana would welcome British protection, and that he could cause a large portion of what is now the central United States to become a British protectorate. Merry forwarded Burr’s suggestion to London. The following year Burr contacted Merry again, asking for British naval support and money. Merry provided Burr with $1,500 and told him that no instructions from London had been forthcoming.
The exact nature of Burr’s plans have been debated ever since. He amassed supplies and support from co-conspirators, began arming militiamen, and prepared to travel downriver on the Ohio and Mississippi Rivers. One of his fellow conspirators came to the conclusion that whatever Burr’s scheme was it would fail, and informed the US government that Burr was planning to create his own empire in the American west. President Jefferson ordered Burr arrested for treason, and the former vice-president was tried before a court with Chief Justice of the Supreme Court John Marshal presiding. Burr was acquitted due to lack of evidence (the Constitution requires the testimony of at least two witnesses). Others of his conspiracy were arrested, but none convicted.