Era
20th century
44
19th century
15
18th century
12
1945-
12
1933-1945
10
1945-1970
9
21st century
9
1783-1865
6
1945-1989
6
Civil War, 1861-1865
6
1918-1933
5
1951-
5
1775-1865
4
1782-1862
4
1789-1809
4
1865-1877
4
1808-1875
3
1809-1865
3
1865-1918
3
1900-1999
3
1901-1936
3
1945-1953
3
1961-1963
3
1989-
3
1997-
3
1066-1485
2
16th century
2
1702-1714
2
17th century
2
1802-1866
2
1805-1859
2
1849-1877
2
1865-1900
2
1879-1964
2
1917-1963
2
1918-1945
2
1942-2011
2
1953-1961
2
1964-1975
2
1971-
2
1985-1991
2
1993-
2
1994-2011
2
Elizabeth II, 1952-
2
Revolution, 1775-1783
2
To 1500
2
To 1775
2
To 70 A.D.
2
1492-1648
1
14th century
1
more ...