- Sep 2 Unilever forms by merger of Margarine Union & Lever Bros
- Sep 2 WOR (NYC) ends affiliation with CBS radio network
- Sep 3 Dow Jones Industrial Average reaches all time high of 381.17, to be shortly followed by the Crash of 1929.
- Sep 5 French premier Aristide Briand requests a United States of Europe
- Sep 11 SF Mayor Rolph inaugurates new pedestrian traffic light system
- Sep 14 A's clinch AL pennant with a 5-0 win over White Sox
- Sep 14 US Men's National Tennis Championship, Forest Hills NY: Bill Tilden wins 7th US title; beats Francis Hunter 3-6, 6-3, 4-6, 6-2, 6-4
- Sep 16 Police shoot at strikers in Maastricht, 2 killed
- Sep 17 British troops begin withdrawal from occupied Germany
- Sep 18 Pirates loss to Braves & clinch NL pennant for the Cubs
- Sep 18 Preston Sturges' "Strictly Dishonorable" premieres in NYC
- Sep 19 Latvia dictator A Woldemaras chased out
- Sep 21 1st legal pass in Canada was thrown by Gerry Seiberling & 1st reception by Ralph Losie of Calgary Altomah-Tigers against Edmonton
Event of Interest
Sep 24 Lt James Doolittle guides a Consolidated N-Y-2 Biplane over Mitchell Field in NY in 1st all-instrument flight
Jimmy Doolittle
- Sep 24 Yanks Tom Zachary ends season 12-0
- Sep 25 Queen-mother Emma opens Antonie van Leeuwenhoek House in Amsterdam
- Sep 26 John Schrober becomes chancellor of Austria
- Sep 28 1st CF interception return for a touchdown (Joe Hess-U of Alberta)
- Sep 30 1st manned rocket plane flight (by auto maker Fritz von Opel)