Aaron Burr, vice president of the United States from 1801 to 1804, had an important connection with the history of Texas. As early as 1796 he proposed that the United States seize the Spanish colonies in the Southwest and establish a great American empire. After leaving the vice presidency in 1804, he made a tour of the western states and became leader of a conspiracy supposed to have been aimed toward invasion of Texas. In 1805 he announced in Kentucky and New Orleans that his life would be devoted to overthrowing Spanish power in America.
In 1806 he negotiated for the purchase of land in the Baron de Bastrop's grant near Natchitoches, Louisiana. There he planned to establish a colony that could be used as a rendezvous for his projected invasion of Mexico, basing his plans on the assumption that the United States would go to war with Spain to avenge Spanish depredations along the Louisiana border. He is also suspected of plotting with British authorities and with the Marqués de Casa Yrujo, a Spanish agent. His intrigues with Yrujo gave rise to the idea that he planned to foment a rebellion against the United States and detach the western states from the central government. On Herman Blennerhasset's island in the Ohio, Burr planned for the colonization of his lands.
His plans miscarried because Gen. James Wilkinson, American military commander in New Orleans Territory, informed President Thomas Jefferson that he had received a coded letter from Burr indicating that Burr meant to seize control of the Mississippi valley. Burr was twice arraigned and tried in Kentucky for instigating an illegal expedition against a friendly nation, but both times he was released for want of sufficient evidence. When his party of colonists set sail from Nashville in December 1808, Jefferson ordered Burr arrested for treason and high misdemeanors.
When Burr arrived at Bayou Pierre, near Natchez, on January 10, he learned that he had been betrayed. On January 17 he surrendered to the governor of Mississippi Territory. After an attempt to escape from the authorities he was tried in Richmond, Virginia. After a prolonged trial Justice John Marshall ruled on October 20, 1807, that Burr was not guilty of treason but was guilty of contemplating an invasion of Spanish territory. He was placed under $3,000 bond.
Burr's exact intentions have never been ascertained, but he probably intended to invade Spanish territory by crossing the Sabine River and marching across Texas. In 1816 he refused the "management" of political affairs of Mexico, but he remained interested in Anglo-American expansion and in Texas colonization and the Texas Revolution, which occurred near the end of his life.