- Apr 8 American Museum of Natural History opens in New York City
- Apr 9 Hudson Bay Company cedes its territory to Canada
- Apr 10 Congress increases number of Supreme Court judges from 7 to 9
- Apr 10 José Martí founds the Cuban Revolutionary Party.
- Apr 12 North Carolina legislature passes anti-Ku Klux Klan Law
Steam Brake
Apr 13 Steam power brake patented by American engineer George Westinghouse
- Apr 16 Ebenezer Bassett, 1st African American diplomat, begins service as Minister to Haiti
- Apr 18 1st international cricket match, held in San Francisco, won by California
- Apr 23 1st professional baseball exhibition game - Cincinnati Red Stockings 24, Cincinnati amateurs 15
- Apr 30 Hawaiian YMCA organized
Admirals
Aviators
Gangsters
Generals
Industrialists
Suffragists