- Jan 9 1st hot-air balloon flight in the US lifts off in Philadelphia, piloted by Jean Pierre Blanchard
- Jan 9 Dutch Prince Willem V establishes 2 brigades Drive Artillery
- Jan 21 Prussia & Russia sign partition treaty, dividing Poland.
- Jan 21 Louis XVI of France is executed by guillotine in Paris, following his conviction for "high treason" by the newly created French Parliament (Convention nationale), during the French Revolution
- Jan 23 2nd Partition of Poland, between Prussia & Russia
- Jan 23 Humane Society of Philadelphia (1st aid society) organized