Aaron Burr (1756-1836), American political leader, was born at Newark, New Jersey, on the 6th of February 1756. His father, the Rev. Aaron Burr (1715-1757), was the second president (1748-1757) of the College of New Jersey, now Princeton University; his mother was the daughter of Jonathan Edwards, the well-known Calvinist theologian. The son graduated from the College of New Jersey in 1772, and two years later began the study of law in the celebrated law school conducted by his brother-in-law, Tappan Reeve, at Litchfield, Connecticut. Soon after the outbreak of the War of Independence, in 1775, he joined Washington's army in Cambridge, Mass. He accompanied Arnold's expedition into Canada in 1775, and on arriving before Quebec he disguised himself as a Catholic priest and made a dangerous journey of 120 m. through the British lines to notify Montgomery, at Montreal, of Arnold's arrival. He served for a time on the staffs of Washington and Putnam in 1776-77, and by his vigilance in the retreat from Long Island he saved an entire brigade from capture. On becoming lieutenant-colonel in July 1777, he assumed the command of a regiment, and during the winter at Valley Forge guarded the "Gulf," a pass commanding the approach to the camp, and necessarily the first point that would be attacked.
In the engagement at Monmouth, on the 28th of June 1778, he commanded one of the brigades in Lord Stirling's division. In January 1779 Burr was assigned to the command of the "lines" of Westchester county, a region between the British post at Kingsbridge and that of the Americans about 15 m. to the north. In this district there was much turbulence and plundering by the lawless elements of both Whigs and Tories and by bands of ill-disciplined soldiers from both armies. Burr established a thorough patrol system, rigorously enforced martial law, and quickly restored order.
He resigned from the army in March 1779, on account of ill-health, renewed the study of law, was admitted to the bar at Albany in 1782, and began to practise in New York city after its evacuation by the British in the following year. In 1782 he married Theodosia Prevost (d. 1794), the widow of a British army officer who had died in the West Indies during the War of Independence. They had one child, a daughter, Theodosia, born in 1783, who became widely known for her beauty and accomplishments, married Joseph Alston of South Carolina in 1801, and was lost at sea in 1813. Burr was a member of the state assembly (1784-1785), attorney-general of the state (1789-1791), United States senator (1791-1797), and again a member of the assembly (1798-1799 and 1800-1801). As national parties became clearly defined, he associated himself with the Democratic-Republicans. Although he was not the founder of Tammany Hall, he began the construction of the political machine upon which the power of that organization is based. In the election of 1800 he was placed on the Democratic-Republican presidential ticket with Thomas Jefferson, and each received the same number of electoral votes.
It was well understood that the party intended that Jefferson should be president and Burr vice-president, but owing to a defect (later remedied) in the Constitution the responsibility for the final choice was thrown upon the House of Representatives. The attempts of a powerful faction among the Federalists to secure the election of Burr failed, partly because of the opposition of Alexander Hamilton and partly, it would seem, because Burr himself would make no efforts to obtain votes in his own favour. On Jefferson's election, Burr of course became vice-president. His fair and judicial manner as president of the Senate, recognized even by his bitterest enemies, helped to foster traditions in regard to that position quite different from those which have become associated with the speakership of the House of Representatives.
Hamilton had opposed Burr's aspirations for the vice-presidency in 1792, and had exerted influence through Washington to prevent his appointment as brigadier-general in 1798, at the time of the threatened war between the United States and France. It was also in a measure his efforts which led to Burr's lack of success in the New York gubernatorial campaign of 1804; moreover the two had long been rivals at the bar. Smarting under defeat and angered by Hamilton's criticisms, Burr sent the challenge which resulted in the famous duel at Weehawken, N.J., on the 11th of July 1804, and the death of Hamilton (q.v.) on the following day. After the expiration of his term as vice-president (March 4, 1805), broken in fortune and virtually an exile from New York, where, as in New Jersey, he had been indicted for murder after the duel with Hamilton, Burr visited the South-west and became involved in the so-called conspiracy which has so puzzled the students of that period. The traditional view that he planned a separation of the West from the Union is now discredited. Apart from the question of political morality he could not, as a shrewd politician, have failed to see that the people of that section were too loyal to sanction such a scheme.
The objects of his treasonable correspondence with Merry and Yrujo, the British and Spanish ministers at Washington, were, it would seem, to secure money and to conceal his real designs, which were probably to overthrow Spanish power in the Southwest, and perhaps to found an imperial dynasty in Mexico. He was arrested in 1807 on the charge of treason, was brought to trial before the United States circuit court at Richmond, Virginia, Chief-Justice Marshall presiding, and he was acquitted, in spite of the fact that the political influence of the national administration was thrown against him. Immediately afterward he was tried on a charge of misdemeanour, and on a technicality was again acquitted. He lived abroad from 1808 to 1812, passing most of his time in England, Scotland, Denmark, Sweden and France; trying to secure aid in the prosecution of his filibustering schemes but meeting with numerous rebuffs, being ordered out of England and Napoleon refusing to receive him. In 1812 he returned to New York and spent the remainder of his life in the practice of law. Burr was unscrupulous, insincere and notoriously immoral, but he was pleasing in his manners, generous to a fault, and was intensely devoted to his wife and daughter.
In 1833 he married Eliza B. Jumel (1769-1865), a rich New York widow; the two soon separated, however, owing to Burr's having lost much of her fortune in speculation. He died at Port Richmond, Staten Island, New York, on the 14th of September 1836.
The standard biography is James Parton's The Life and Times of Aaron Burr (first edition, 1857; enlarged edition, 2 vols., Boston and New York, 1898). W.F. McCaleb's The Aaron Burr Conspiracy (New York, 1903) is a scholarly defence of the West and incidentally of Burr against the charge of treason, and is the best account of the subject; see also I. Jenkinson, Aaron Burr (Richmond, Ind., 1902). For the traditional view of Burr's conspiracy, see Henry Adams's History of the United States, vol. iii. (New York, 1890).