The diploma thesis deals with the historical figure of Thaddeus Kosciuszko, the national hero of the United States, Belarus and Poland, and his pursuit of freedom within the historical context of the eighteenth century, particularly, the American Revolutionary War and the Polish Uprising of 1794. The evolution and philosophy of freedom are disclosed by the description of various philosophical approaches towards the concept. The detailed description of Kosciuszko's contribution to the achievement of the American independence from the British and the struggle for the Polish sovereignty is showed in the thesis.The diploma thesis deals with the historical figure of Thaddeus Kosciuszko, the national hero of the United States, Belarus and Poland, and his pursuit of freedom within the historical context of the eighteenth century, particularly, the American Revolutionary War and the Polish Uprising of 1794. The evolution and philosophy of freedom are disclosed by the description of various philosophical approaches towards the concept. The detailed description of Kosciuszko's contribution to the achievement of the American independence from the British and the struggle for the Polish sovereignty is showed in the thesis.