In 1900, the National League contracted to 8 teams, and in 1901 the American League joined as the "Junior Circuit" with 8 teams as well. The league remained at 16 teams until 1961.
The face of baseball in the 1920s, Babe Ruth really helped usher the sport into national prominence. His production was unmatched at the time, and his 467 home runs during the decade are the most anyone has ever hit in a single decade.
Rogers Hornsby won seven batting titles during the decade, including four seasons in which he hit over .400, and he did it while displaying impressive power as well, leading the league in home runs twice and RBI four times.
With Lou Gehrig not taking over as a full-time starter until 1925, he slides down the top players list behind one of the most underrated players of the era in Harry Heilmann. The Tigers outfielder won four batting titles, hitting over .390 each time.
The decade was as thin as any on pitching stars, though Eppa Rixey, Red Faber, Herb Pennock, Dolf Loque and an aging Pete Alexander were all excellent. On the offensive side, outfielders Ken Williams and Goose Goslin both had impressive numbers, and Al Simmons was an absolute beast for a few years.