I Thaddeus Kosciuszko being just in my departure from America do hereby declare and direct that should I make no other testamentary disposition of my property in the United States I hereby authorise my friend Thomas Jefferson to employ the whole thereof in purchasing Negroes from among his own or any others and giving them Liberty in my name, in giving them an education in trades or otherwise and in having them instructed for their new condition in the duties of morality which may make them good neigh bours good fathers or mothers, husbands or vives and in their duties as citizens teaching them to be defenders of their Liberty and Country and of the good order of Society and in whatsoever may Make them happy and useful, and I make the said Thomas Jefferson my executor of this. Kościuszko left his American estate to buy the freedom of black slaves, including Jefferson's own, and to educate them for independent life and work. In the document, Kościuszko, over six decades before the American Civil War, pleaded for the emancipation of America's Negro slaves. Before leaving that same year (1798) he wrote out a will, which he entrusted to Jefferson as executor. His friend Thomas Jefferson provided him with a passport in a false name and arranged for his secret departure to France.

In 1798 Kościuszko decided to leave the United States and return to the Russian-controlled sector of the former Polish–Lithuanian Commonwealth. In the 1850s, what was left of the money in Kościuszko's U.S. Kościuszko returned to Europe in 1798 and lived there until his 1817 death in Switzerland. Jefferson's refusal incited discussion in the 19th, 20th, and 21st centuries. Jefferson refused the executorship and the will was beset by legal complications, including the discovery of later wills.

Tadeusz Kościuszko (1746–1817), a prominent figure in the history of the Polish–Lithuanian Commonwealth and the American Revolution, made several wills, notably one in 1798 stipulating that the proceeds of his American estate be spent on freeing and educating African-American slaves, including those of his friend Thomas Jefferson, whom he named as the will's executor.

Hitchens on jefferson