Kościuszko was born in February 1746, in a manor house on the Mereczowszczyzna estate in Brest Litovsk Voivodeship, then Grand Duchy of Lithuania, a part of the Polish–Lithuanian Commonwealth, now the Ivatsevichy District of Belarus.

A close friend of Thomas Jefferson, with whom he shared ideals of human rights, Kościuszko wrote a will in 1798, dedicating his U.S. assets to the education and freedom of the U.S. slaves.

[9] Kościuszko was born in February 1746 in a manor house on the Mereczowszczyzna estate near Kosów in Nowogródek Voivodeship, Grand Duchy of Lithuania, a part of the Polish–Lithuanian Commonwealth.

[18][19][20][21] His paternal family was originally Ruthenian[16] and traced their ancestry to Konstanty Fiodorowicz Kostiuszko, a courtier of Polish King and Grand Duke of Lithuania Sigismund I the Old.

King Stanisław August Poniatowski established a Corps of Cadets (Korpus Kadetów) in 1765, at what is now Warsaw University, to educate military officers and government officials.

Faced with a difficult choice between the rebels and his sponsors—the King and the Czartoryski family, who favored a gradualist approach to shedding Russian domination—Kościuszko chose to leave Poland.

When Kościuszko returned home in 1774, he found that his brother Józef had squandered most of the family fortune, and there was no place for him in the Army, as he could not afford to buy an officer's commission.

[39] With the British in complete control of the high ground, the Americans realized their situation was hopeless and abandoned the fortress with hardly a shot fired in the siege of Ticonderoga.

[40] Encumbered by their huge supply train, the British began to bog down, giving the Americans the time needed to safely withdraw across the Hudson River.

His judgment and meticulous attention to detail frustrated the British attacks during the Battle of Saratoga,[14] and Gates accepted the surrender of Burgoyne's force there on 16 October 1777.

[46] During this campaign, Kościuszko was placed in command of building bateaux, siting the location for camps, scouting river crossings, fortifying positions, and developing intelligence contacts.

During the unsuccessful siege, he suffered his only wound in seven years of service, bayonetted in the buttocks during an assault by the fort's defenders on the approach trench that he was constructing.

On 1 February 1790, he reported for duty in Włocławek, and wrote in a letter after a few days, calling the local inhabitants "lazy" and "careless", in contrast to "good and economical Lithuanians".

In the same letter, Kosciuszko begged general Franciszek Ksawery Niesiołowski for a transfer to the Army of the Grand Duchy of Lithuania, but his wishes were not granted.

[74] Kościuszko argued that the peasants and Jews should receive full citizenship status, as this would motivate them to help defend Poland in the event of war.

The Crown Army was judged too weak to oppose the four enemy columns advancing into West Ukraine, and began a fighting withdrawal to the western side of the Southern Bug River, with Kościuszko commanding the rear guard.

At the Battle of Dubienka (18 July 1792), Kościuszko repulsed a numerically superior enemy, skilfully using terrain obstacles and field fortifications, and came to be regarded as one of Poland's most brilliant military commanders of the age.[80].

[80][87] On 24 July 1792, before Kościuszko had received his promotion to lieutenant-general, the King shocked the army by announcing his accession to the Targowica Confederation and ordering the Polish–Lithuanian troops to cease hostilities against the Russians.

He stayed there until summer, but despite the growing revolutionary influence, the French paid only lip service to the Polish cause and refused to commit themselves to anything concrete.

[93] This came as a shock to the Targowica Confederates, who had seen themselves as defenders of centuries-old privileges of the magnates but had hardly expected that their appeal for help to the Tsarina of Russia would further reduce and weaken their country.

Kościuszko issued a public reproach, writing, "What happened in Warsaw yesterday filled my heart with bitterness and sorrow", urging, successfully for no more lynchings in the area.

The news in one of them came as a shock to him, causing him, still in his wounded condition, to spring from his couch and limp unassisted to the middle of the room and exclaim to General Anthony Walton White, "I must return at once to Europe!"

[106] He immediately consulted then Vice President of the United States Thomas Jefferson, who procured a passport for him under a false name and arranged for his secret departure for France.

"[111] In the will, Kościuszko left his American estate to be sold to buy the freedom of black slaves, including Jefferson's own, and to educate them for independent life and work.

In return for his prospective services, Kościuszko demanded social reforms and restoration of territory, which he wished would reach the Dvina and Dnieper Rivers in the east.

[138] One of the first examples of a historical novel, Thaddeus of Warsaw, was written in Kościuszko's honor by the Scottish author Jane Porter; it proved very popular, particularly in the United States, and went through over eighty editions in the 19th century.

Kościuszko also appears in non-Polish literature, including a sonnet by Samuel Taylor Coleridge, another by James Henry Leigh Hunt, poems by John Keats and Walter Savage Landor, and a work by Karl Eduard von Holtei.

[138] In 1933, the U.S. Post Office issued a commemorative stamp depicting an engraving of "Brigadier General Thaddeus Kosciuszko," a statue of Kościuszko that stands in Washington, D.C.'s Lafayette Square, near the White House.

[142] There are statues of Kościuszko in Poland at Kraków (by Leonard Marconi), which was destroyed by German forces during the World War II occupation and was later replaced with a replica by Germany in 1960[143] and Łódź (by Mieczysław Lubelski);[120] in the United States at Boston,[143] West Point,[143] Philadelphia (by Marian Konieczny),[143] Detroit[144] (a copy of Leonard Marconi's Kraków statue),[145] Washington, D.C.,[120] Chicago,[120] Milwaukee[120] and Cleveland;[120] and in Switzerland at Solothurn.

The time capsule is believed to date either from 1828 when it was erected by the Corp of Cadets, or 1913 when Polish clergy and laity of the United States donated a statue of Kosciuszko to sit atop the column.