DUPORTAIL, Louis Lebeque, Chevalier, soldier, born in France; died at sea in 1802. He was educated at the military school of Mezieres, and considered an excellent engineer. He was one of four French officers engaged by Dr. Franklin and Silas Deane to serve in the American army (see biographies DUCOUDRAY and DEANE), they being the only ones engaged by the express authority of congress. He was appointed colonel of engineers on his arrival promoted to be brigadier general, 17 November 1777, and major general, 16 November 1781. He had charge of the engineering operations at the siege of Yorktown, and was one of the general officers particularly mentioned by Washington in his dispatches after the capitulation. He returned to France, and in 1788 was named marechaldecamp. Owing to his intimate relations with Lafayette, whose political views he approved, he was, on 16 November 1790, appointed minister of war; but, sharing in the misfortunes of his friend and patron, he was denounced in the assembly for mal-administration of his office, and resigned, 3 December 1791.

He was then given a military appointment in Lorraine; but, being warned in 1792 that a serious accusation was about to be brought against him, left the army, and, after living two years in concealment, retired to America. He was recalled by the events of the lath Brumaire, but died on the homeward passage. During his service in the American army the Chevalier Duportail was much impressed by the timidity and bad generalship of the British officers. In 1777 he wrote: "The success of the Americans is not owing to their strength or bravery, but to the astonishing conduct of the British forces, to the slowness and timidity of the British general." Referring to the battle of Brandywine, he writes:" If the English had followed up their advantage that day Washington's army would have been spoken of no more; since that time, also, General Howe has, in all his operations, exhibited such slowness and timidity as to strike me with astonishment. With 30,000 men, an active, enterprising general must reduce this country."