Era
20th century
62
19th century
30
Civil War, 1861-1865
28
18th century
14
21st century
14
1861-1865
11
1865-1950
11
Revolution, 1775-1783
11
1775-1783
9
1945-
9
1945-1989
9
1933-1945
8
1989-
6
2001-2009
6
1775-1865
5
1980-
5
1783-1865
4
1789-1799
4
1917-1945
4
1918-1933
4
1953-1961
4
Revolution, 1789-1799
4
To 1775
4
1783-1809
3
1865-1877
3
1865-1918
3
1865-1933
3
1865-1945
3
1900-1999
3
1917-1936
3
1936-1953
3
1946-
3
1951-
3
1961-1963
3
1985-1991
3
1994-
3
To 1865
3
17th century
2
1800-1899
2
1809-1865
2
1865-1900
2
1886-1918
2
1890-1969
2
1901-1953
2
1908-1957
2
1913-1921
2
1945-1953
2
1945-1970
2
1945-1991
2
1960-
2
more ...