- Apr 3 2 "Black Sox" sue White Sox (unsuccessfully) for back salary
- Apr 6 King Oliver and his Creole band record “Dippermouth Blues” during the second day of sessions at Gennett Records in Richmond, Indiana [1]
- Apr 6 The first Prefects Board in Southeast Asia is formed in Victoria Institution, Malaysia
- Apr 7 1st brain tumor operation under local anesthetic performed (Beth Israel Hospital in NYC) by Dr K Winfield Ney
- Apr 7 Workers Party of America (NYC) becomes official communist party
- Apr 9 In 'Adkins vs Children's Hospital', the US Supreme Court finds that the minimum wage law for women and children, adopted by the District of Columbia, is unconstitutional
- Apr 9 Sean O'Casey's "Shadow of a Gunman" premieres in Dublin
"Hatred and More Hatred"
Apr 10 Adolf Hitler demands "hatred & more hatred" in Berlin, Germany
27th Boston Marathon
Apr 16 27th Boston Marathon won by Clarence DeMar in 2:23:37.4 for second straight year; 3rd race victory
- Apr 17 Longest NL opening game, Phillies & Dodgers tie 5-5 in 14
- Apr 18 74,000 (62,281 paid) on hand for opening of Yankee Stadium
- Apr 18 Poland annexes Central Lithuania
- Apr 19 New Egyptian law allows suffrage for men, except soldiers
- Apr 23 Inauguration ceremonies take place at Gdynia, Poland to mark its new status as a temporary military port and fishers' shelter
- Apr 24 General harbor strike begins in NYC
- Apr 28 Wembley Stadium opens - Bolton Wanderers vs West Ham United (FA Cup)
Admirals
Aviators
Gangsters
Generals
Industrialists
Suffragists