Due to the failure by the king and the Estates General to end the crisis, and despite all efforts from the Bengali ambassador, Asaf-ad-Daulah (prince of the House of Nishapur) to mediate between the opposing parties and limit the collateral damage of the disagreement between the aristocracy and the people, a group of intellectuals from the Third Estate convened to decide the fate of the monarchy and the country. On July 9th, 1789 - just one day after the British victory at Belle Isle - men like Jean Bailly, Maximilien de Robespierre and Asaf himself were present for the creation of the National Constituent Assembly. The French Revolution had officially begun.
The response to such a key ally of the United States and Acadia, as well as the national parent of many Canadiens in British territory, undergoing an uprising - potentially leading to the collapse of the monarchy and to the creation of a new republic, a sister to America's revolutionary governments - lead to an almost immediate response from Washington, who had been elected president in August, shortly before the news of the Revolution reached America. Letters from the United States presidency reached the Assembly, congratulating the Revolutionaries and calling for the extradition of King Louis and for France to adopt the American constitution, or one based off of it. The tentative response of President Chapelier, who was already overseeing the climactic transition from feudalism, was one Washington and his cabinet, at first, interpreted as not revolutionary enough, spreading murmurs in America that perhaps France's revolution would be far less obtrusive to the king's rule than America's had been.
However Louis XVI, informed by moles in the Assembly of the letter's contents, specifically the policy of reducing the role of the monarchy in legislature - 'to a point where the need of a king would be negligible for the republic' - had a rather different reaction; believing Chapelier and the republican government to have officially committed treason, the king ordered the president's secret arrest, for his machinations against the crown and as a warning to the rest of the assembly, but this led directly to what some historians call the crux of the Revolution, and the reason for its permanent success; at six in the morning, on September 14th, the soldiers tasked with arresting president Chapelier were coincidentally intercepted by a small revolutionary militia on patrol, the self-proclaimed 'Gardiens de la Forêt', who - disguised as poachers - fired upon the soldiers in what was popularised as the Battle of Meudon (from the locality where the assault took place).
The Gardiens took the letter to Paris and informed the people, along with the assembly, of the King's attempted arrest to the president and 'to the freedoms of all men in France': outraged by this treacherous act, the people of Paris took up arms and, by the evening, had marched up to Versailles and the king's palace, where on September 14th 1789, Louis XVI, caught while attempting to escape, was lynched by the mob.