Aaron Burr

In 1807 Aaron Burr was prosecuted for TREASON and high misdemeanor in the federal circuit court in Richmond, Virginia, with U.S. Supreme Court Chief Justice JOHN MARSHALL presiding as a trial judge. Despite evidence that Burr had been plotting to raise a rebellion and overtake a portion of the western territories in the United States and other evidence that Burr was planning to lead an unauthorized invasion of Mexico, the defendant was acquitted by a jury on both the treason and high misdemeanor charges.

Aaron Burr served as the nation's third vice president from 1801–1805, having lost the 1800 presidential election after the U.S. House of Representatives broke an electoral deadlock by naming THOMAS JEFFERSON president and Burr vice president. Although Burr contemplated running for president again four years later, those ambitions came to an end when he was indicted for murdering ALEXANDER HAMILTON in a duel on July 11, 1804.

Later that same month, Burr, now disaffected with American politics, met with Britain's minister to the United States, Anthony Merry, who subsequently reported to his government that Burr "was endeavoring to effect a separation of the western part of the United States" via military action. In early 1805 Burr, while still acting as the vice president of the United States, contacted Spanish minister, Marques de Casa Yrujo, to discuss the same subject. The governments of both Great Britain and Spain declined to offer Burr any financial or military assistance.

When his term as vice president expired, Burr headed west to raise a military force that would either invade Mexico or forcefully sever the southwestern United States into an independent nation led by Burr himself. The former vice president first met with another malcontent, Herman Blennerhassett, on Blennerhassett Island, located in the Ohio River, then part of Virginia. A year later Burr joined forces with General James Wilkinson on Blennerhassett Island, where they assembled a force of unknown size to carry out Burr's plan. Burr left the island before any actions were taken to implement the plan.

After Burr departed, Wilkinson had second thoughts about the plan and informed President Jefferson of their rebellious preparations. Jefferson issued a proclamation calling for the suppression of the conspiracy. Federal authorities arrested Burr in March 1807 while he was trying to flee into Spanish Florida. The former vice president was brought back to Virginia where he stood trial before Chief Justice John Marshall (early Supreme Court justices performed double duty as appellate judges on the nation's high court and as trial judges in their designated circuit court) and state trial judge Cyrus Griffin. Bail was set at $5,000.

After hearing testimony from Wilkinson, the GRAND JURY for the Virginia federal circuit court indicted Burr on June 24, 1807. The indictment charged him with one count of treason and one count of high misdemeanor for "unlawfully, falsely, maliciously, and traitorously … intending to raise and levy war" against the United States.

The trial began on August 10, 1807, and ended less than a month later, on September 1, 1807. Jefferson, motivated in part by personal vindictiveness against Burr, declared in a special message to Congress during the trial that Burr's guilt had been "placed beyond question." Jefferson then gave George Hay, the U.S. attorney in charge of the prosecution, incriminating evidence to offer against Burr. Jefferson also dangled pardons as enticements to any co-conspirators who agreed to turn state's evidence.

But the prosecution had two major problems. First, the linchpin of the treason charge was the alleged OVERT ACT of assembling a military force on Blennerhassett Island for the purpose of waging war against the United States. The indictment said this act occurred on December 10, 1806, a date on which all defense and prosecution witnesses agreed that Burr was not on the island, but instead hundreds of miles away.

Second, Chief Justice Marshall instructed the jurors that they could still convict Burr of treason for being a co-conspirator to the crime, so long as at least two witnesses provided testimony that some overt act was committed in furtherance of the conspiracy. But General Wilkinson was the only witness who testified as to Burr's involvement in the alleged crime. The jury returned a verdict of "not guilty" after deliberating for only 25 minutes.

On September 9, 1807, the trial for the high misdemeanor began, again with Chief Justice Marshall and Cyrus Griffin presiding. Prosecutor Hay called more than 50 witnesses to testify against the defendant. But the jury again acquitted Burr. Hay then filed a motion to prosecute Burr for treason in Ohio, alleging that the defendant conspired to levy war against the U.S. government in that jurisdiction as well. Marshall listened to five weeks of testimony concerning the motion and then on October 20 ruled that Burr could only be tried for misdemeanor charges in Ohio. Finally, Hay ceased efforts at prosecuting Burr any further.