- Mar 9 Charles Graham of NY granted first US patent for artificial teeth
- Mar 19 Boston, Massachusetts incorporated as a city
- Mar 22 NY Horticultural Society founded
- Mar 30 Congress combines East & West Florida into Florida Territory
- Mar 31 Massacre of the population of the Greek island of Chios by soldiers of the Ottoman Empire following a rebellion attempt, (later depicted by artist Eugène Delacroix)