- Sep 2 Salon of Varietes opens in Amsterdam
- Sep 5 The First Opium War begins in China
- Sep 6 Cherokee Nation unites and ratifies constitution at Tahlequah, Oklahoma
- Sep 6 Great fire in New York
- Sep 9 English scientist and astronomer John Herschel takes 1st glass plate photograph
- Sep 11 1st Canadian track & field meet held (Caer Howell Grounds)
- Sep 20 1st railroad in Netherland opens (Amsterdam-Haarlem)