In March 1871, ten of the United States' most powerful professional baseball clubs met in Brooklyn, New York. Out of that meeting came the sport's first major league: the National Association of Professional Baseball Players. The Philadelphia Athletics, with a record of 21-7, captured the new circuit's first championship.

From the National Association through the American League's inaugural season in the final year of the century, this work is a year-by-year statistical history of the teams and players of the nineteenth century's major leagues. The teams are listed by league, with full rosters and complete statistics for each player. An introductory section for each year places the league in historical perspective. Exhaustive team and player indexes are also included.