Effigies of his likeness were hung and burned throughout the country and the threat of additional charges from individual states forced him into exile overseas in Europe.
[2] Burr's true intentions remain unclear and, as a result, have led to varying theories from historians: some claim that he intended to take parts of Texas and the newly acquired Louisiana Purchase of 1803 for himself, while others believe he intended to try to conquer Mexico to the southwest (then a Royal Spanish colonial province of the Kingdom of Spain in the Viceroyalty of New Spain, in the Americas, part of the world-wide Spanish Empire), or even as the gossip extended to wild accusations of conquering even the entirety of the continent of North America.
As Burr told several of his colleagues, he suggested to Merry that the British might regain power in the Southwest if they contributed guns and money to his expedition.
Burr offered to detach Louisiana from the Union in exchange for a half million dollars and a British fleet in the Gulf of Mexico.
Merry wrote, "It is clear Mr. Burr... means to endeavour to be the instrument for effecting such a connection—he has told me that the inhabitants of Louisiana ... prefer having the protection and assistance of Great Britain.
He provided friendship, support, and most importantly, access to Blennerhassett Island which he owned on the Ohio River, about 2 miles (3 km) below what is now Parkersburg, West Virginia.
On July 27, 1805, Burr stopped at a stand near the Duck River along the Natchez Trace to attend a party celebrating the signing of the Treaty of the Chickasaw Nation.
"[citation needed] In early 1806, Burr contacted the Spanish diplomat and future Prime Minister, Carlos Martínez de Irujo y Tacón and told him that his plan was not just western secession, but the capture of Washington, D.C. Irujo wrote to his masters in Madrid about the coming "dismemberment of the colossal power which was growing at the very gates" of New Spain.
Following the events in Kentucky, Burr returned to the West later in 1806 to recruit more volunteers for a military expedition down the Mississippi River.
The Governor of Ohio grew suspicious of the activity there, and ordered the state militia to raid the island and seize all supplies.
In February and March 1806, the federal attorney for Kentucky, Joseph Hamilton Daveiss, wrote Jefferson several letters warning him that Burr planned to provoke a rebellion in Spanish-held parts of the West, in order to join them to areas in the Southwest and form an independent nation under his rule.
T[ruxton] is gone to Jamaica to arrange with the admiral on that station, and will meet at the Mississippi—England—Navy of the United States are ready to join, and final orders are given to my friends and followers—it will be a host of choice spirits.
Burr's plan of operations is to move rapidly from the falls on the 15th of November, with the first five hundred or one thousand men, in light boats now constructing for that purpose—to be at Natchez between the 5th and 15th of December—then to meet Wilkinson—then to determine whether it will be expedient in the first instance to seize on or pass by Baton Rouge.
He is thoroughly informed of the plans and intentions of Burr, and will disclose to you as far as you inquire, and no further—he has imbibed a reverence for your character, and may be embarrassed in your presence—put him at ease and he will satisfy you —29th July.
They intended to reach New Orleans, but in Bayou Pierre, 30 miles north of Natchez, they learned that a bounty was out for Burr's capture.
He was acquitted due to lack of evidence of treason, as Chief Justice John Marshall did not consider conspiracy without actions sufficient for conviction.
Senator, New York State Attorney General and Assemblyman, and finally vice president under Jefferson, Burr adamantly denied and vehemently resented all charges against his honor, his character or his patriotism.
[13] Burr was charged with treason for assembling an armed force to take New Orleans and separate the Western from the Atlantic states.
George Hay, the prosecuting U.S. Attorney, compiled a list of over 140 witnesses, one of whom was Andrew Jackson, who previously invited Burr to stay at his house when he was on the run.
The high misdemeanor charge was dropped when the government was unable to prove that the expedition had been military in nature or directed toward Spanish territory.
Though Marshall vowed to consider Jefferson's office and avoid "vexatious and unnecessary subpoenas", his ruling was significant because it suggested that, like all citizens, the president was subject to the law.
Intention to divide the union was not an overt act: "There must be an actual assembling of men for the treasonable purpose, to constitute a levying of war.
"[21] In contrast, lawyer and author David O. Stewart concludes that Burr's intention included "acts that constituted the crime of treason, but that in the context of 1806, "the moral verdict is less clear."
[22] Immediately following the acquittal, straw effigies of Burr, Blennerhassett, Martin, and Marshall were hanged and burned by angry mobs.
Following an unsuccessful court-martial ordered by President James Madison in 1811, he was allowed to return to his military command in New Orleans.
In 1842, a "Justitia" writing in the New-York American connected the Burr conspiracy and Jackson's association with Sam Houston, writing:[28] "I will now say in general terms, that the committee that undertook the defense of Gen. Jackson, at the period of his first nomination for the presidency, against the charge that he was a participator in Burr's conspiracy, do not even pretend to clear him of that part of it relating to the conquest of Mexico, but only of what relates to the dismemberment of this Union.
Gen. Jackson was fully aware of all his movements in getting up his Texan expedition; notwithstanding which, he entertained him in the most cordial manner, as he had previously done to Burr; and instead of adopting measures to check his operations, countenanced him in every way he could, as far as he dared to do, under existing circumstances.
How happened it, that the two arch-conspirators against the integrity of the Mexican republic, should, at different and distant periods, make Jackson's domicil their rendezvous?