Era
20th century
69
21st century
51
Civil War, 2011-
30
1989-
23
1957-2011
13
1992-
13
1991-
12
18th century
11
19th century
9
2000-
9
1945-
8
2003-
7
1969-
6
1685-1750
5
1945-1989
5
1965-
5
1924-
4
1945-1955
4
1953-1985
4
2001-
4
1867-1959
3
1936-
3
1943-
3
1952-
3
1987-
3
Civil War, 1861-1865
3
16th century
2
1710-1782
2
17th century
2
1846-1935
2
1866-1895
2
1909-1972
2
1913-
2
1917-2002
2
1918-1998
2
1933-1945
2
1949-
2
1954-
2
1968-2001
2
1971-1981
2
1976-2002
2
1980-
2
1993-
2
1993-2001
2
2009-2017
2
2016
2
Devonian
2
Holocene
2
Precambrian
2
-1963
1
more ...