Births on September 18

Eloísa Mafalda, Brazilian actress

Mafalda Theotto (September 18, 1924 – May 16, 2018), known professionally as Eloísa Mafalda, was a Brazilian actress.

12 Feb

Rhapsody in Blue
George Gershwin's Rhapsody in Blue received its premiere in a concert titled "An Experiment in Modern Music", in Aeolian Hall, New York, by Paul Whiteman and his band, with Gershwin playing the piano.
25 Mar

Second Hellenic Republic
On the anniversary of Greek Independence, Alexandros Papanastasiou proclaims the Second Hellenic Republic.
21 May

Leopold and Loeb
University of Chicago students Richard Loeb and Nathan Leopold, Jr. murder 14-year-old Bobby Franks in a "thrill killing".
4 Aug

Soviet Union
Diplomatic relations between Mexico and the Soviet Union are established.
23 Nov

Andromeda Galaxy
Edwin Hubble's discovery, that the Andromeda "nebula" is actually another island galaxy far outside of our own Milky Way, is first published in The New York Times.