Editing 1921 (section)

=== September ===
{{Main|September 1921}}
* [[September 1]] &ndash; [[Poplar Rates Rebellion]]: Nine members of the [[borough council]] of [[Poplar, London]], are arrested.{{citation needed|date=May 2025}}
* [[September 8]] &ndash; [[Margaret Gorman]], 16, wins the Golden Mermaid trophy at a beauty pageant in [[Atlantic City, New Jersey]]; officials later dub her the first [[Miss America]].{{citation needed|date=May 2025}}
* [[September 13]] &ndash; [[White Castle (restaurant)|White Castle]] [[hamburger]] restaurant opens in [[Wichita, Kansas]],<ref>{{cite news|url=http://www.kansas.com/2011/05/12/1845732/buy-sliders-here-for-a-day.html|title=White Castle marks 90th anniversary with one-day return to Wichita|newspaper=[[Wichita Eagle]]|access-date=2012-05-13|date=2011-05-12|first=Beccy|last=Tanner|archive-date=June 27, 2014|archive-url=https://web.archive.org/web/20140627195442/http://www.kansas.com/2011/05/12/1845732/buy-sliders-here-for-a-day.html|url-status=dead}}</ref> foundation of the world's first [[fast food]] chain.
* [[September 21]] &ndash; The [[Oppau explosion]] occurs at [[BASF]]'s [[nitrate]] factory in Oppau, Germany; 500–600 are killed.{{citation needed|date=May 2025}}
* [[September 28]] &ndash; [[Sauerländer Heimatbund]] is founded in [[Meschede]], Germany.<ref>{{cite book|first=Peter |last=Bürger|title="Voll bereit für die Neue Zeit": Deutschnationale, militaristische und NS-freundliche Dichtungen Christine Kochs 1920-1944|url=https://books.google.com/books?id=zt-LDwAAQBAJ&pg=PA52|date=2019|publisher=BoD – Books on Demand|isbn=978-3-7494-0910-5|pages=52|language=de}}</ref>