Era
20th century
25
1900-1999
20
19th century
9
1939-1945
6
Early 19th century
6
Revolution, 1775-1783
4
1783-1850
3
1860-1918
3
17th century
2
1809-1865
2
1900-1945
2
1918-
2
1918-1938
2
1945-
2
1975-
2
1976
2
Colonial period, ca. 1600-1775
2
Since 1918
2
Since 1975
2
1473-1543
1
1600-1699
1
1656-1680
1
1809-1849
1
1837-1901
1
1883
1
18th century
1
1922-
1
1935-
1
1940-1991
1
1942-1945
1
1945-1991
1
19the century
1
Civil War, 1861-1865
1
Occupation, 1939-1945
1