Era
20th century
1,858
21st century
1,081
19th century
871
18th century
377
To 1500
286
17th century
285
Cretaceous
255
16th century
211
2000-
183
1946-
170
Tertiary
157
2009-
156
1945-
141
1991-
137
1989-
126
Precambrian
108
Quaternary
107
Paleozoic
96
Eocene
94
Permian
89
1724-1804
85
Cenozoic
84
1564-1616
83
Civil War, 2011-
77
Miocene
77
1960-
73
Civil War, 1861-1865
69
Jurassic
69
Pleistocene
68
Ordovician
67
1947-
66
1949-
66
Early modern, 1500-1700
66
Devonian
63
Mississippian
62
Mesozoic
60
1970-
58
2016
58
Pennsylvanian
58
1990-
53
1945-1989
52
Triassic
52
1933-1945
50
1959-
46
2001-
46
1997-
44
Holocene
44
1980-
42
1979-
41
1950-
40
more ...