From the 1760s to the 1790s, the upheavals of the Polish-Lithuanian Commonwealth were connected to revolutionary changes in ideas and power on both sides of the Atlantic. This chapter explains the paralysis of the Commonwealth and traces the fiery trajectory of its final three decades. The Enlightenment revealed much in the Polish-Lithuanian world in need of renewal, but it also lit up potential for growth. Ideas generated abroad interacted fruitfully with home-grown intellectual traditions. The dilemma posed by the ancient Roman historian Sallust – “perilous liberty” or “tranquil servitude”? – briefly seemed capable of resolution as “orderly freedom,” after the Four Years’ Sejm (parliament) of 1788-1792 had acclaimed the Constitution of May 3, 1791. However, the country’s neighbors – Russia, Prussia and Austria – destroyed this felicitous future by the second and third partitions in 1793 and 1795. The chapter is framed by the figure of Tadeusz Kościuszko (1746-1817), hero of the War of American Independence and leader of the 1794 insurrection in Poland-Lithuania against Russian dominance, “the purest son of liberty” (according to Thomas Jefferson), who personified the “Atlantic Revolution” on both sides of the ocean.