ARNOLD, BENEDICT (1741-1801), American soldier, was born in Norwich, Conn., on Jan. 14, 1741. He was the great grandson of Benedict Arnold (1615-78), thrice colonial governor of Rhode Island between 1663 and 1678; and was the fourth in direct descent to bear the name. He received a fair education but was not studious, and his youth was marked by the same way wardness which characterized his whole career. At 15 he ran away from home and took part in an expedition against the French, but he soon deserted and returned home. In 1762 he settled in New Haven, where he engaged successfully in trade with the West Indies. Immediately after the battle of Lexington, Arnold led the local militia company, of which he was captain, to Cambridge, and on April 29, 1775, proposed to the Massa chusetts committee of safety an expedition against Crown Point and Ticonderoga. The offer was accepted, and as a colonel of Massachusetts militia he was directed to enlist the men necessary for the undertaking. He was forestalled, however, by Ethari Allen (q.v.), acting on behalf of some members of the Connecticut assembly. Under him, reluctantly waiving his own claim to com mand, Arnold served as a volunteer; and soon afterwards, Massa chusetts having angered Arnold by sending a committee to make an inquiry into his conduct, he resigned and returned to Cam bridge. He was then ordered to co-operate with Gen. Richard Montgomery in the invasion of Canada. Starting with 1,Ioo men from Cambridge on Sept. 17, 1775, he reached Gardiner, Me., on the loth, advanced through the Maine woods, and, after suffering terrible hardships, his little force reached Quebec on Nov. 13. The garrison had been forewarned, and Arnold was compelled to await the coming of Montgomery from Montreal. The combined at tack on Dec. 31, 1775, failed ; Montgomery was killed, and Arnold was severely wounded. Arnold, who had been commissioned a brigadier general, remained in Canada until the following June, being after April in command at Montreal.
Some time after the retreat from Canada, charges of miscon duct and dishonesty were brought against him. These charges were tardily investigated by the Board of War, which in a report made on May 23, 1777, declared that his "character and conduct" had been "cruelly and groundlessly aspersed." Having constructed a flotilla on Lake Champlain, Arnold engaged a greatly superior British fleet near Valcour Island (Oct. 11, 1776), and after in flicting severe loss on the enemy, made his escape under cover of night. This engagement was the first between British and Ameri can fleets. Arnold's brilliant exploits had drawn attention to him as one of the most promising of the Continental officers, and had won for him the friendship of Washington. Nevertheless, when in Feb. Congress created five new major generals, Arnold, although the ranking brigadier, was passed over, in favour of his juniors. At this time it was only Washington's urgent persuasion that prevented Arnold from leaving the service. Two months later while he was at New Haven, Governor Tryon's descent on Danbury took place; and Arnold attacked the British with such vigour at Ridgefield (April 27, 1777), that they escaped to their ships with difficulty.
In June 1778, Washington placed him in command of Phil adelphia. Here he soon came into conflict with the state authori ties. In the social life of Philadelphia, largely dominated by families of Loyalist sympathies, Arnold was the most conspicuous figure; he lived extravagantly, entertained lavishly, and in April 1779, took for his second wife, Margaret Shippen (176o-18o4), the daughter of Edward Shippen (1729-1806), a moderate Loy alist. Early in Feb. 1779, the executive council of Pennsylvania, presided over by Joseph Reed, one of his most persistent enemies, presented to Congress eight charges of misconduct against Arnold. In April 1779, Congress, though throwing out four charges, re ferred the other four to a court-martial. Despite Arnold's de mand for a speedy trial, it was December before the court was convened. It was probably during this period of vexatious delay that Arnold, always sensitive and now incited by a keen sense of injustice, entered into a secret correspondence with Sir Henry Clinton with a view to joining the British service. On Jan. 26, 1780, the court, before which Arnold had ably argued his own case, rendered its verdict, practically acquitting him of all inten tional wrong, but directing Washington to reprimand him for two trivial offences. Arnold, who had expected absolute acquittal, was inflamed with a burning anger that even Washington's kindly reprimand, couched almost in words of praise, could not subdue.
It was now apparently that he first conceived the plan of be traying some important post to the British. With this in view he sought and obtained from Washington (Aug. 178o) command of West Point, the key to the Hudson valley. Arnold's offers now became more explicit, and, in order to perfect the details of the plot, Clinton's adjutant-general, Major John Andre, met him near Stony Point on the night of Sept. 21. On the 23rd, while returning by land, Andre with incriminating papers was captured, and the officer to whom he was entrusted unsuspectingly sent in formation of his capture to Arnold, who was thus enabled to escape to the British lines. Arnold, commissioned a brigadier general in the British army, received £6,315 in compensation for his property losses, and was employed in leading an expedition into Virginia which burned Richmond, and in an attack upon New London (q.v.) in September, 1781. In Dec. 1781, he re moved to London and was consulted on American affairs by the king and ministry, but could obtain no further employment in the active service. Disappointed at the failure of his plans and embittered by the neglect and scorn which he met in England, he spent the years 1787-91 at St. John, N.B., once more engaging in the West India trade, but in 1791 he returned to London, and after war had broken out between Great Britain and France, was active in fitting out privateers. He gradually sank into melan cholia, and died in London June 14, 1801.