Never has an American trial produced such an impressive set of key players：

　　the defendant—— Aaron Burr， founding father， Vice President， and slayer of Alexander Hamilton in their famous duel three years earlier；

　　the trial judge——John Marshall， Chief Justice of the United States Supreme Court （and the most important justice in history）；

　　the force behind the prosecution——Thomas Jefferson， author of the Declaration of Independence and president of the United States；

　　defense attorneys——Edmund Randolph and Luther Martin， both delegates to the Constitutional Convention and among the most prominent men of the day； prosecutors—— Charles Lee， former Attorney General， and William Wirt， future presidential candidate.

　　The high-stakes treason trial of Aaron Burr came at an unstable time， both in Europe and in America. The American and French revolutions worried traditional European powers， Great Britain and Spain， who were determined to keep the radical new doctrine from undermining the power of their royalty. Meanwhile， Napoleon's empire-building produced sustained military conflict on the Continent.

　　The United States seemed on the verge of a war with Spain， even as the Administration struggled to preserve neutrality. Americans west of the Alleghenies rejoiced in President Jefferson's acquisition of the Louisiana Territory， but boundary disputes and Spanish prohibitions on Louisiana residents' entry into Nueva Espana created resentment and threats of reprisal. The Viceroy of Mexico， allied generally with western Indians， sent troops to the Sabine River to protect the Spanish frontier from invasion by United States citizens. Most Westerners saw Spain as tyrannical and viewed Texas and Florida as a rightful part of the United States. Many of these same Westerners expressed a willingness to take Spanish territory by force. Meanwhile， Spain also worried about the designs of residents of its own dominion （especially Mexico）， recognizing that the unprivileged masses had grown resentful of Spanish authority.

　　The Burr Conspiracy

　　In this troubled time， the end of President Jefferson's first term， Aaron Burr stepped down from the Vice Presidency， and began preparations for a military expedition that was either—— depending upon whose views one solicited——treasonous or patriotic. At its core， however， the Burr Conspiracy clearly was about conquest and adventure.

　　The Burr Conspiracy had its origins in a series of discussions over the winter of 1804-05 between Burr and his longstanding friend， General James Wilkinson. The two served together in the Quebec campaign of 1775-76. Over the years they often corresponded in a cipher invented by Wilkinson. Wilkinson was an intriguer of the first-order who had formerly been the head of a party in the West that favored a separation of the western states from the Atlantic states.

　　Burr left Washington for a tour of the West in March of 1805. His first stop was in Philadelphia， where he met with Anthony Merry， the British Minister to the United States. Merry reported details of his conversation in a letter to London：

　　"I am encouraged to report to your Lordship the substance of some secret communications which [Burr] has sought to make to me since he has been out of office……Mr. Burr has mentioned to me that the inhabitants of Louisiana [the lands recently purchased from France] seem determined to render themselves independent of the United States and the execution of their design is only delayed by the difficulty of obtaining previously an assurance of protection and assistance from some foreign power……It is clear that Mr. Burr means to endeavor to be the instrument for effecting such a connection……He pointed out the great commercial advantage which his Majesty's dominions in general would derive from furnishing almost exclusively （as they might through Canada and New Orleans） the inhabitants of so extensive a territory……Mr. Burr observed it would be too dangerous and even premature to disclose to me at present the full extent and detail of the plan he had formed……In regard to military aid， he said， two or three frigates and the same number of smaller vessels to be stationed at the mouth of the Mississippi to prevent its being blockaded by such force as the United States could send， and to keep open the communications with the sea would be the whole that would be wanted； and in respect to money the loan of about one hundred thousand pounds would， he conceived， be sufficient for the immediate purposes of the enterprise."

　　On April 29， 1805， Burr reached Pittsburgh， where he planned to meet with General Wilkinson， the new Governor of the just-organized Louisiana Territory. But Wilkinson had been delayed， so Burr left a letter for him and set off down the Ohio River in a specially-prepared boat （called by Burr his "ark"）。

　　In early May， Burr reached Blennerhassett's Island， a three-hundred acre piece of land in the river. The island belonged to an Irish gentleman named Harman Blennerhassett. Blennerhassett invited Burr to dinner. The conversation that ensued——lasting until eleven o'clock in the evening——would forever link Blennerhassett's Island with the Burr Conspiracy. The precise nature of the plans discussed over dinner is not known， but some inkling may be gleaned from a letter sent by Blennerhassett later that year to Burr：

　　"I should be honored in being associated with you， in any contemplated enterprise you would permit me to participate in……Viewing the probability of a rupture with Spain，……I am disposed， in the confidential spirit of this letter， to offer you and my friends' and my own services in any contemplated measures in which you may embark."

　　Continuing down the river， Burr met with others who would later be connected with his conspiracy. In Cincinnati， Burr visited with his friend， former Ohio Senator Jonathan Dayton， later indicted with Burr for treason. Burr left his "ark" in Louisville to travel overland to Nashville， where he received a very enthusiastic welcome of dinners and balls from the local population. In Nashville， Burr stayed as the guest of General Andrew Jackson. After resuming his river voyage， Burr finally met General Wilkinson at Fort Massac. （Wilkinson would later describe his conversations with Burr as perfectly legitimate， but there is strong suspicion that this opportunity was used to detail plans for Burr's western aggression.） Wilkinson provided Burr with "an elegant barge， sails， colors， ten oars， with a sergeant and ten able， faithful hands，" as well as a letter of introduction to friends in New Orleans， Burr's ultimate destination.

　　Burr loved New Orleans enough to want to settle there， he said， "were it not for [his daughter] Theodosia and her boy." He used his time in New Orleans to gauge public opinion concerning Mexico and to discuss possible enterprises with persons sympathetic to a Mexican insurrection. Burr's principal contact in New Orleans， wealthy merchant and political leader Daniel Clark， promised $50，000 in support of Burr's projects and subsequently traveled to Mexico to gather information on the strength of Spanish fortresses and the attitudes of the people to Spanish control. Clark told at least one witness that he "might be a duke" in the new empire that would rise after the Burr expedition's conquest .

　　Burr left New Orleans in late July of 1805， beginning a four-month tour that included another meeting with General Wilkinson in St. Louis. It was at this time， according to Wilkinson's later and probably self-serving report， that he said he began to suspect Burr of treasonous intentions. He quoted Burr as denouncing "the imbecility of the Government" and that "the people of the western country were ready for revolt." Wilkinson claimed to have responded to Burr's interpretation of western sentiments， "Surely， no person was ever more mistaken！ The western people disaffected to the Government？ They are bigoted to Jefferson and democracy？"

　　Burr's long western sojourn finally ended with his arrival back in Washington in October. Over the winter of 1806-06， Burr met frequently with disaffected military leaders such as Commodore Truxton and General Eaton， urging that he join in his western adventure. He sent letters to supporters he had identified on his western trip and enlisted the full support of his beloved daughter Theodosia.

　　In mid-summer， Burr （and Theodosia and her young child） set off again for western lands. Burr continued to sound out potential backers for his military expedition. In western Pennsylvania， hoping to enlist the support of influential Colonel Morgan and his two sons， Burr made the fatal mistake of expressing plans which his host found shocking. Morgan wrote a letter to President Jefferson summarizing his conversation with Burr， setting in motion the Administration effort that would eventually put an end to Burr's dreams and lead to his arrest and trial. Morgan would later provide testimony of his conversation with Burr at his 1807 trial：

　　After dinner I spoke of our fine country. I observed that when I first went there， there was not a single family between the Allegheny mountains and the Ohio； and that by and by we should have congress sitting in this neighborhood or at Pittsburg. We were allowed to sport these things over a glass of wine： "No， never，" said Colonel Burr， "for in less than five years you will be totally divided from the Atlantic states." The colonel entered in