Era
20th century
49
Revolution, 1775-1783
44
1981-1989
34
1945-
30
1900-1999
28
1775-1783
26
1945-1989
21
19th century
20
1900 - 1999
19
1775 - 1783
18
1981-
17
Since 1945
16
18th century
15
1981 - 1989
14
1989-1993
12
Civil War, 1861-1865
12
1970-
11
1989-
11
1975-
10
1800-1899
9
1869-1934
9
Colonial period, ca. 1600-1775
9
Since 1970
9
1869 - 1934
8
1975-1985
8
1809-1865
7
1861-1865
7
1882-1945
7
1969-1974
7
Since 1900
7
16th century
6
1700-1799
6
1800 - 1899
6
1933-1945
6
1960-1980
6
1993-
6
1484-1566
5
1861 - 1865
5
1890-1969
5
1945-1953
5
1964-1975
5
1969 - 1974
5
1980-
5
1980-2020
5
1993-2001
5
Pleistocene
5
To 1810
5
To 1863
5
1743-1826
4
1775-1865
4
more ...