| 1858 | Formation of National Association of Baseball Players NABBP) |
| Admission fee charged to all-star baseball series at Fashion Course Racetrack in New York. | |
| 1860 | Debut of James Creighton, first acknowledge professional player |
| Publication of Beadle's Dime Baseball Player | |
| 1862 | William Cannemeyer of Brooklyn charges 10-cent admission fee to games at Brooklyn's Union Grounds. |
| 1866 | Cincinnati's Red Stockings, first openly professional baseball team, formed. |
| 1869 | Cincinnati's Red Stockings National Tour |
| 1871 | Formation of National Association of Professional Baseball Players |
| 1876 | National League Founded |
| 1882 | American Association Founded |
| 1890 | Brotherhood War |
| 1891 | American Association Folds |
| National League Expands to 12 Teams | |
| 1900 | National League Contracts to Eight Teams |
| 1901 | American League becomes major League |
| 1903 | National and American League Sign Peace Agreement |
| First World Series |