Two Party System

Events

1789 - 1799
1831 - 1832
1860 - 1861
1865 - 1867
1880 - 1890
1896 - 1897
1910 - 1911
1930 - 1940
1960 - 1975
1972 - Approx. 1973
1980 - 1981
1988 - 1989