KOSCIUSZKO, Tadeusz (THADDEUS) (kos-se-us'-ko), Polish patriot, born near Novogrndek, Lithuania, 12 February, 1746; died in Solothurn, Switzerland, 15 October, 1817. He was descended from a noble Lithuanian family, studied at the military academy of Warsaw, and, completing his education in France at the expense of the state, returned to Poland, entered the army, and rose to the rank of captain. An unrequited passion for the daughter of the Marquis of Lithuania induced him to leave Poland in 1775 and offer his assistance to the Americans in their war for independence. The number of foreign auxiliary officers had become numerous, and Washington had complained to congress, in October, 1776, that he was unable to employ many of them, owing to their ignorance of English.

Kosciuszko, however, arrived with letters of recommendation from Benjamin Franklin to Washington, who inquired what he could do. " I come to fight as a volunteer for American independence," answered Kosciuszko. "What can you do?." asked Washington. "Try me," was the reply. He received his commission as a colonel of engineers on 18 October, 1776, and repaired to his post with the troops under General Gates, who described him as "an able engineer, and one of the best and nearest draughtsmen that he ever saw." and selected him for the northern service, ordering him, "after he had made himself thoroughly acquainted with the works, to point out where and in what manner the best improvements and additions could be made thereto."

Kosciuszko therefore planned the encampment and post of Gates's army at Berets Heights, near Saratoga, from which, after two well-fought actions, Burgoyne found it impossible to dislodge the Americans. Kosciuszko was subsequently the principal engineer in executing the works at West Point. He became one of Washington's adjutants, and aided General Nathanael Greene in the unsuccessful siege of Ninety-Six, receiving for his services the thanks of congress and the brevet of brigadier-general, 13 October, 1783. One of Washington's latest official acts was to intercede with congress for the bestowal of these honors. He was also made a member of the Society of the Cincinnati.

At the end of the war he returned to Poland, where he lived several years in retirement. When the Polish army was reorganized in 1789, he was appointed a major-general, and fought in defense of the constitution of 3 May, 1791, under Prince Poniatowski, against the Russians. He was in the battle of Zielence, 18 June, 1792, and in that of Dubienka, 17 July, 1792, where, with only 4,000 men, he kept 15,000 Russians at bay for six hours, making his retreat without great loss. But the patriots were overwhelmed by numbers, and when King Stanislas submitted to the second partition of Poland, Kosciuszko resigned his commission and retired to Leipsic, where he received from the national assembly the citizenship of France. He determined to make a second effort for Poland, and a rising of his countrymen was secretly planned. Kosciuszko was elected dictator and general-in-chief.

On 24 March, 1794, he suddenly appeared in Cracow, issued a manifesto against the Russians, and hastily collected a force of about 5,000 peasants, armed mostly with scythes. At Raclawice he routed a Russian corps that was almost twice as strong, and returned in triumph to Cracow. He committed the conduct of government affairs to a national council that was organized by himself, and after receiving re-enforcements moved forward in quest of the Russian army. The march was opposed by the king of Prussia at the head of 40,000 men, and Kosciuszko, whose force was only 13,000, was defeated at Szczekociny, 6 June, 1794.

Unable to check the prevailing anarchy, Kosciuszko resigned his dictatorship and retired with his army to Warsaw, and defended it against the Prussians and Russians, whom he compelled to raise the siege. Austria now took part against him with 150,000 men, and he was routed at Maciejowice, 10 October, 1794. Kosciuszko fell covered with wounds, he was imprisoned in St. Petersburg for two years, until the death of Catherine, when the Emperor Paul gave him his liberty, with many marks of esteem. The czar, in releasing him, offered him his sword, but Kosciuszko refused to accept it, saying, "I have no need of a sword; I have no country to defend." Subsequently his countrymen in the French army of Italy presented him with the sword of John Sobieski.

On crossing the Russian frontier he returned to the czar the patent of his pension and every testimonial of Russian favor, and passed the rest of his life in retirement. He visited the United States in 1797, where he was received with distinction, and obtained from congress a grant of land, in addition to the pension that he had received after the Revolutionary war. He then resided in Fontainebleau until 1814, engaged in agriculture. When Napoleon was about to invade Poland in 1806 he wished to employ Koseiuszko, who, being under parole not to fight against Russia, refused to enlist, and the proclamation to the Poles that appeared in the "Moniteur" under his name in 1806 he declared to be a forgery. In 1816 he removed to Solothurn, Switzerland, and in the following year sent a deed of manumission to all the serfs on his Polish estate. His death was caused by a fall from his horse over a precipice.

The Emperor Alexander had him interred beside Poniatowski and Sobieski in the cathedral of Cracow, near which city the people raised to his memory a mound 150 feet high, the earth of which was brought from every great battle-field of Poland. From a fancied resemblance to this mound the loftiest mountain in Australia has received the name of Mount Kosciuszko. A monument of white marble, designed by John H. B. Latrobe, and represented in the illustration, was erected to his memory at West Point by the United States military academy cadet corps of 1828, at a cost of $5,000. See Chodzko's " Histoire militaire, politique et privee de Kosciuszko" (Paris, 1837); and Falkenstein's "Leben Kosciuszko's" (Leipsic, 1825).