Era
20th century
59
1900-1999
24
1953-1985
24
19th century
22
1985-1991
13
21st century
13
18th century
11
17th century
9
1945-1989
9
Civil War, 1861-1865
9
1933-1945
7
1955-2017
7
1968-1989
7
1945-1991
6
1949-
6
1775-1865
5
1945-
5
1991-
5
Civil War, 1642-1649
5
1809-1865
4
1861-1865
4
1976-2002
4
2000-2099
4
Since 1900
4
1700-1899
3
1783-1865
3
1921-
3
1921-1989
3
1925-
3
1945-1992
3
1953-1991
3
1963-1969
3
1970-1991
3
1975-
3
1980-1989
3
1989-
3
1993-
3
2001-2009
3
2002-
3
1368-1644
2
1568-1627
2
1600-1699
2
1601-1658
2
1613-1682
2
1800-1999
2
1846-1950
2
1865-1945
2
1865-1950
2
1882-1945
2
1895-1972
2
more ...