20th century 27
1809-1865 14
Mississippian 10
19th century 9
Devonian 6
Quaternary 5
1805-1844 4
Ordovician 4
To 1865 4
1831-1897 3
1867-1959 3
1875- 3
1929 3
1951- 3
1956- 3
1965- 3
Civil War, 1861-1865 3
Paleozoic 3
1778-1865 2
1800-1844 2
1849-1861 2
1861-1865 2
1865-1950 2
1899-1947 2
1949- 2
Cambrian 2
Pennsylvanian 2
Pleistocene 2
To 1950 2
17th century 1
1804-1861 1
1815-1861 1
1815-1864 1
1815-1886 1
1830-1899 1
1837-1921 1
1849-1877 1
1853-1942 1
1855-1926 1
1856-1924 1
1860-1935 1
1861-1896 1
1861-1934 1
1866-1944 1
1867-1936 1
1878-1945 1
1879-1925 1
1882-1967 1
1885-1933 1
1885-1966 1
1886-1939 1
1898-1919 1
18th century 1
1902-1976 1
1905-1972 1
1909-1981 1
1922-1981 1
1924-2014 1
1929-1968 1
1930-2014 1
1934- 1
1940- 1
1942- 1
1946- 1
1948-1969 1
1954- 1
1964- 1
1968- 1
Carboniferous 1
Earthquake, 1987 1
Permian 1
Riot, 1967 1
Silurian 1
To 1763 (New France) 1
To 1803 1
To 1875 1
To 1964 1