Era
20th century
455
19th century
237
1900-1999
150
1865-1950
119
1951-
99
21st century
63
1865-1877
48
1800-1899
41
1945-1989
41
Civil War, 1861-1865
35
2000-2099
34
1989-
31
2009-2017
30
Since 1900
30
1775-1865
25
1861-1865
23
1933-1945
23
1994-
21
1975-
20
2001-2009
20
1961-1978
17
1978-1989
16
1800-1950
15
1963-1969
15
To 1964
15
2008
14
Since 1951
14
1980-
13
1800-1999
12
18th century
12
1809-1865
11
1865-1900
11
1865-1999
11
1836-1909
10
1877-1964
10
1900 - 1999
10
1945-
10
1909-1948
9
Since 1865
9
1815-1861
8
1868-1963
8
1948-1994
8
1979-1997
8
1993-
8
1775-1783
7
1783-1865
7
1789-1869
7
1849-1877
7
1865-
7
1865-1933
7
more ...