Era
20th century
493
19th century
297
1900-1999
133
To 1912
130
To 1950
94
1800-1899
83
21st century
69
1900 - 1999
57
1951-
52
1848-1929
49
Tertiary
47
Civil War, 1861-1865
46
1867-1959
42
2000-2099
37
1834-1902
36
Paleozoic
36
Cenozoic
33
1851-1887
32
Permian
31
Precambrian
31
Triassic
27
1800 - 1899
26
Mesozoic
26
1848-1950
24
Quaternary
24
1912-1950
23
Cretaceous
19
1939-1945
18
19e siècle
18
From 65 to 230 million years ago
18
1866-1895
17
From 65 million years ago
17
Pliocene
17
Since 1951
17
1829-1909
16
1932-
16
1934-
16
1945-
16
From 2 to 65 million years ago
16
1644-1711
15
1843-1914
15
Jurassic
15
1848-
14
20e siècle
14
Cambrian
14
1871
13
From 190 to 230 million years ago
13
From 230 to 570 million years ago
13
From 570 million to 5 billion years ago
13
Miocene
13
more ...