Why Was Aaron Burr Indicted for Treason?

Aaron Burr, while probably most famous for killing Alexander Hamilton in a duel, was also notorious for his scheme to capture New Orleans and create his own empire. Aaron Burr had served four years as Thomas Jefferson’s vice president but stepped down when Jefferson was re-elected in 1804. Soon after leaving office, he was scheming to take over New Orleans and other western states that were only loosely loyal to the United States after years of political upheaval in the region.

In August 1804, Aaron Burr contacted Anthony Merry, the British foreign minister to the U.S., seeking support for his plan to detach the western states. Burr didn’t receive support, but that didn’t deter him. Aaron Burr found powerful support in General James Wilkinson, the new governor of the Louisiana Territory. Since Wilkinson controlled the military in the region, Aaron Burr’s plan was to rendezvous with the general after raising an army of locals along the Mississippi River.

Aaron Burr spent much of 1805 traveling along the Mississippi meeting with sympathizers like Harman Blennerhassett, an eccentric Irishman who agreed to help by allowing Burr to use his estate as a meeting point for his army. Daniel Clark, a wealthy merchant from New Orleans, agreed to front $50,000 US Dollars (USD) to support a Mexican insurrection that was supposed to initiate Louisiana’s secession. Other support for the scheme came from the Mexico Society, a group of New Orleans businessmen who favored annexation with Mexico.

As Aaron Burr gathered the needed equipment, rumors of his plot caught up with him. He was summoned to the federal court in Kentucky three times over the course of 1806 and tried for treason. Each time he was acquitted, but he began to lose Wilkinson’s support. In the spring of 1807 he set off to meet his army at Blennerhassett’s home not realizing that Wilkinson had already alerted Jefferson of his plot.

Despite a cease and desist order from Jefferson and a only a small showing of men at Blennerhassett’s, Burr continued on his trek toward New Orleans. He finally surrendered at Bayou Pierre, just north of New Orleans after he saw a copy of a decoded letter, the famous Cipher Letter, he had sent to Wilkinson published in a local newspaper. He was tried at the Supreme Court for treason and acquitted because of John Marshall’s decision to define treason narrowly, according to the U.S. Constitution.