Era
20th century
54
1900-1999
32
19th century
25
Revolution, 1775-1783
24
1945-
22
18th century
21
Civil War, 1861-1865
19
Colonial period, ca. 1600-1775
15
1939-1945
10
1809-1865
8
1945-1991
7
1979-
7
1945-1980
6
1951-
6
Early 19th century
6
Revolution, 1917-1921
6
1800-1837
5
1869-1934
5
1900-1945
5
20e siècle
5
Since 1979
5
1760-1789
4
1917-1921
4
1918-1945
4
1975-
4
Since 1945
4
1706-1790
3
1783-1850
3
1783-1865
3
1809-1817
3
1860-1918
3
1898-1946
3
1933-1945
3
1945-1989
3
1973-
3
1980-
3
Since 1918
3
To 1775
3
War of 1812
3
1699-1777
2
1732-1799
2
1751-1836
2
17th century
2
1819-1892
2
1837-1901
2
1861-1865
2
1881-1945
2
1892-1984
2
1914-
2
1917 - 1921
2
more ...