- Sep 1 Napoleon III captured at Sedan
- Sep 2 Napoleon III surrenders to Prussian armies at the Battle of Sedan
- Sep 4 The Third French Republic proclaimed as French overthrow Emperor Napoleon III (who ironically was the elected president of the Second French Republic) after his defeat by Prussia at Sedan
- Sep 6 Ship sinks in Gulf of Biscay; 483 die
- Sep 8 Netherlands and Britain sign "Koelietraktaat" an agreement to allow Indian contract workers from Calcutta to work in sugar plantations in Suriname
- Sep 10 Dutch Jurist Cooperation forms
- Sep 15 Dutch 1st Chamber abolishes Capital punishment (20-18)
- Sep 15 11th British Golf Open: Tom Morris, Jr. shoots a 149 at Prestwick Golf Club
- Sep 19 Siege of Paris by Prussian Forces begins (lasts until January 28 1871)
Event of Interest
Sep 20 Capture of Rome by Italian army, Pope Pius IX surrenders to King Victor Emmanuel which unifies Italy and ends 1,116 year reign of Papal States
Victor Emmanuel II
Boss Tweed