Era
20th century
251
1945-1989
117
19th century
100
1900-1999
95
1989-
88
21st century
64
2001-2009
60
1951-
56
1865-1950
51
2009-
44
1946-
41
Civil War, 1861-1865
38
1800-1899
37
1918-1961
34
1775-1865
33
1971-1981
31
1815-1861
27
Since 1945
26
1849-1877
25
1933-1945
24
1809-1858
23
1925-1968
22
1993-2001
22
To 1865
22
1783-1865
21
Revolution, 1775-1783
21
1981-1989
19
18th century
17
1932-2009
17
1948-
16
1969-1974
16
1981-2001
16
2009-2017
16
1775-1783
15
1861-1865
15
1943-
15
1963-1969
15
2000-2099
15
World War, 1914-1918
15
1977-1981
14
1793-1863
13
1908-1957
13
Since 1951
13
1940-
12
1947-2017
12
1786-1836
11
1865-1933
11
1901-1953
11
1913-1994
11
1945-1953
11
more ...