1785: John Hancock is reelected governor of Massachusetts. Shay's Rebellion never happens.
1787: The Constitutional Convention never happens as Shay's Rebellion never provides the necessary excuse.
1789: France, inspired by the American example, erupts in revolution. Thomas Jefferson and others on the American Left (although left-right terminology would not be in use for a few more years) are sympathetic toward the French.
1790: The French pass the Civil Constitution of the Clergy, basically nationalizing the Catholic Church in France. Pope Pius VI denounces this threatens to excommunicate anybody who is ordained by or worships in the churches under the Civil Constitution of the Clergy.
1792: The French abolish the monarchy, imprisoning the king, and the National Assembly becomes the sovereign ruler of France. The other European powers invade, starting the French Revolutionary War. In the Americas, the Confederation splits up due to disagreement over whether or not to aid France. Although no American states decide to go through with a declaration of war on the European ancien regime, numerous individual American citizens head to France to repay the French for the aid provided to their homeland in the recent War of Independence.
1793: The French National Assembly formally disestablishes and bans the Catholic Church after the Papal States declares war on France. The French establish Deism as the new state religion, although all non-Catholics are tolerated to the dismay of Jacobins like Maximilien Robespierre. The French decide to adopt a new Calendar of Reason which they set to retroactively begin on the Autumn Equinox in 1792. The calendar consisted of 12 months of 30 days with 5 or 6 Leap Days at the end of the year. The French also adopted a new decimal time system, which divided each day into 10 hours of 100 minutes of 100 seconds.
1795: The French Revolutionary War ends in victory for France. In the peace treaty France agrees with its neighbors to permit open immigration so that conservative Frenchmen could move elsewhere and radicals from those countries can move to France. Catholicism is made legal once again in France although Catholics are not permitted to vote. Post-Revolutionary France begins to model itself after ancient Athens.
1796: Thomas Paine's The Age of Reason is published. The British, fearing that the radical Paine who had been instrumental in inciting 2 revolutions would lead Britain into Revolution and undermine the Church of England, ban his book. Likewise, the Catholics put it on the Index Librorum Prohibitorum. It is also banned in Russia as a threat to the Orthodox Church and in Prussia as a danger to the state. However, The Age of Reason becomes a bestseller in America, which experiences a massive surge in Deism.
1797: New York and Pennsylvania form an alliance against Virginia and attempt to take over portions of the Ohio territory, leading to the start of the Ohio War. The war would last for 3 years.
1799: Maryland and North Carolina align with New York and Pennsylvania in an attempt to take parts of the land south of the Ohio River for themselves and contain Virginian imperialism.
1800: Virginia surrenders and cedes part of North Western Virginia to Maryland. New York claims the northernmost part of the Ohio Territory (mostly corresponding to OTL Michigan and Wisconsin), which is separated from New York by some Canadian territory. Pennsylvania takes a large chunk of territory north of the Ohio River and south of New York's territory (corresponding to the northern parts of OTL Indiana, Illinois, and Ohio). Maryland claims a small strip of land around both sides of the Ohio River (OTL southern Illinois, Indiana, and Ohio and parts of northern Kentucky). North Carolina basically extended their state westward (OTL Tennessee). Virginia retained the remainder (portions of OTL southern Kentucky).
1805: Great Britain agrees to sell a strip of land in Canada south of Toronto to New York, averting a possible war. After seeing what happened to Virginia, The British were worried that New York might bring in Massachusetts, Vermont, New Hampshire, Pennsylvania, and France as allies and carve up Canada amongst themselves.