Era
20th century
521
19th century
393
1900-1999
218
To 1500
213
21st century
197
18th century
157
1800-1899
126
2000-2099
92
17th century
85
1945-
81
1951-
68
16th century
60
Civil War, 1861-1865
55
To 476
54
1800-1999
42
1700-1799
40
Since 1945
40
Colonial period, ca. 1600-1775
33
1786-1847
25
476-1517
25
1989-
23
Tertiary
22
1935-
21
1600-1799
20
1900-2099
20
1775-1865
19
1949-
19
1997-
19
To 146 B.C.
19
1991-
18
Since 1951
18
1981-
17
Revolution, 1910-1920
17
1700-1899
15
1939-1945
15
1980-
15
1500-1599
14
War of 1812
14
Cretaceous
12
To 1517
12
1600-1699
11
1979-1997
11
Cenozoic
11
Geschichte
11
To 1810
11
To 500
11
1517-1789
10
1929
10
1971-
10
711-1516
10
more ...