Era
20th century
28
1900-1999
7
21st century
6
Civil War, 1861-1865
5
1900 - 1999
3
1961-1975
3
Revolution, 1775-1783
3
1837-1950
2
1900-2099
2
Since 1933
2
1765-1947
1
1775-1783
1
1824-1907
1
1854
1
1861-1865
1
1863-1947
1
1869-1954
1
1890-1937
1
1903-1940
1
1933-
1
1933-1945
1
1933-1953
1
1939-1945
1
1945 - 1955
1
1945-1955
1
1948-9999
1
1949-
1
1961 - 1975
1
1965-
1
1970
1
1980
1
1991-2003
1
2000-2099
1
2003-
1
British occupation, 1765-1947
1
Since 1865
1
Since 1991
1