Era
2009-
108
Civil War, 1861-1865
83
Cretaceous
77
To 1846
68
21st century
51
To 1803
50
2001-2009
43
1866-1895
40
2003-
34
Cenozoic
33
20th century
31
1854-1861
29
Revolution, 1835-1836
28
1960-
27
Tertiary
27
1948-
26
1991-
26
Quaternary
26
1945-
25
1989-
24
1951-
23
1979-
23
1952-
22
1980-
22
2001-
22
1815-1875
21
Paleozoic
21
1786-1847
20
1964-
19
Miocene
19
1643-1687
18
1956-
18
1965-
18
1988-
18
Jurassic
18
Pliocene
18
1946-
17
1950-
17
1959-
17
1961-
17
1966-
17
Mesozoic
17
1862-1865
16
1949-
16
1963-
16
1846-1850
15
1953-
15
1993-
15
1794-1876
14
1967-
14
more ...