I've added some more topics. I don't know if they're the broadest and most important, though. In many cases, I'm sure they're not, but I don't know which ones would be so considered. Please, please check and edit the entries in your areas of expertise. See talk:Wikipedia arranged by topic.
... 1904 in sports
The second Summer Olympic Games are held in St. Louis, Missouri, USA
Births:
January 5 - Jeane Dixon[?], astrologer (+ 1997)
January 10 - Ray Bolger, ...