The 1900s were the beginning of what has become known in baseball as "the modern era." The rules were finally in a relatively stable form and one that would remain so over the next century. The game itself, though, was very different. This was the heart of the Deadball Era, a time of reduced offensive levels throughout the baseball world (which meant North America and Cuba for all intents and purposes).
In the major leagues, the formation of the American League as a major league in 1901 presented the National League with its first rival in a decade - and the one that would last the longest. The addition of a second league led to players jumping from team to team as the leagues were involved in open player warfare in the first half of the decade. The two-league system also enabled the revival of major postseason competitions, with the creation of the World Series. Top major league position players of the decade were clearly Nap Lajoie in the AL and Honus Wagner in the NL. Ed Walsh, Christy Mathewson, Three-Finger Brown and Cy Young were among the notable hurlers.
In the minor leagues, the major change was the addition of the classification system to rank leagues, starting in 1902. It was a fluid time for the most part in terms of leagues. The major ones were the Eastern League (later to become the International League) and American Association.
With baseball now segregated, all-black teams slowly increased in number, though they still did not resemble a league in any fashion and top black teams rarely played each other. They did begin playing competitively against white major league teams in exhibition competitions, though, and also did well in their tours of Cuba, which began this decade.
In the international baseball world, only the Cuban Winter League was a major presence. Major leaguers like George McQuillan and Rip Hagerman began to appear, as did black stars such as Pete Hill, Rube Foster and Home Run Johnson to compete with native Cuban greats like José Muñoz. Almost all major leaguers were from the US during this period.
|Years||American League||National League||Postseason|
|1900||1900 NL||Chronicle-Telegraph Cup|
|1901||1901 AL||1901 NL|
|1902||1902 AL||1902 NL|
|1903||1903 AL||1903 NL||1903 WS|
|1904||1904 AL||1904 NL|
|1905||1905 AL||1905 NL||1905 WS|
|1906||1906 AL||1906 NL||1906 WS|
|1907||1907 AL||1907 NL||1907 WS|
|1908||1908 AL||1908 NL||1908 WS|
|1909||1909 AL||1909 NL||1909 WS|
- Robert K. Fitts: Issei Baseball: The Story of the First Japanese American Ballplayers, University of Nebraska Press, Lincoln, NE, 2020. ISBN 978-1-4962-1348-8
- Mark S. Halfon: Tales from the Deadball Era: Ty Cobb, Home Run Baker, Shoeless Joe Jackson and the Wildest Times in Baseball History, Potomac Books, University of Nebraska Press, Lincoln, NE, 2014. ISBN 978-1612346489
- Bill James: "The 1900s", in The New Bill James Historical Baseball Abstract, The Free Press, New York, NY, 2001, pp. 71-93.
- Chuck Kimberly: The Days of Wee Willie, Old Cy and Baseball War Scenes from the Dawn of the Deadball Era, 1900–1903, McFarland, Jefferson, NC, 2014. ISBN 978-0-7864-9401-9
- Chuck Kimberly: The Days of Rube, Matty, Honus and Ty: Scenes from the Early Deadball Era, 1904–1907, McFarland, Jefferson, NC, 2019. ISBN 978-1-4766-7610-4
- Marc Okkonen: Baseball Memories, 1900-1909: An Illustrated Chronicle of the Big Leagues' First Decade, Sterling Publishing Company, New York, NY, 1992. ISBN 978-0806987286
- Ronald T. Waldo: Characters from the Diamond: Wild Events, Crazy Antics, and Unique Tales from Early Baseball, Rowman & Littlefield, Lanham, MD, 2016. ISBN 978-1-4422-5868-6