1998 – Arizona joins the league as an expansion franchise, and Milwaukee transfers from the American League, giving the NL sixteen teams.
1994 – The league is split into three divisions.
1993 – Colorado and Florida were added as expansion teams. The league now has 14 teams split into two seven-team divisions.
1969 – Montreal and San Diego added to form a 12-team league. The league is split into two six-team divisions.
1966 – Milwaukee Braves move to Atlanta.
1965 – Houston Colt .45s renamed Astros.
1953 – Boston Braves move to Milwaukee.
1900 – Baltimore, Cleveland, Louisville, and Washington are eliminated. The league has eight teams.
1892 – Baltimore, Louisville, St. Louis, and Washington are added. The league now has 12 teams.
1890 – Indianapolis and Washington fold, Brooklyn and Cincinnati enter the league.
1889 – Detroit folds and Cleveland re-enters the league.
1887 – Kansas City and St. Louis fold, Indianapolis and Pittsburgh join the league.
1886 – Buffalo and Detroit fold, Kansas City and Washington join.
1885 – Cleveland folds and St. Louis enters the league.
1883 – Troy and Worcester fold, New York and Philadelphia join the league.
1881 – Cincinnati folds and Detroit enters the league.
1880 – Worcestor joins the league, Syracuse folds.
1879 – Buffalo, Cleveland, Syracuse, and Troy join the league. Indianapolis and Milwaukee fold. The league now boasts eight teams.
1878 – Indianapolis, Milwaukee and Providence join the league. St. Louis, Louisville and Hartford fold. The league still has six teams.
1877 – New York and Philadelphia both fold. The league plays with six teams.
1876 – The National League is born with eight charter members: Boston, Chicago, Cincinnati, Hartford, Louisville, New York, Philadelphia and St. Louis.
Only the Cubs (Chicago) and Braves (Boston, Milwaukee and Atlanta) remain from the original franchises that made up the 1876 National League.