Era
20th century
48
19th century
32
21st century
21
1969-
8
1964-
6
1984-
6
17th century
5
18th century
5
1967-
5
1970-
5
2001-2009
5
1977-
4
1978-
4
1982-
4
1985-
4
1989-
4
1960-
3
1961-
3
1965-
3
1968-
3
1971-
3
1979-
3
1981-
3
1983-
3
1986-
3
Civil War, 1861-1865
3
Famine, 1845-1852
3
1917-1948
2
1919-
2
1923-
2
1929
2
1943-
2
1946-
2
1950-
2
1952-
2
1957-
2
1962-
2
1966-
2
1974-
2
1975-
2
1979-1997
2
2009-
2
Colonial period, ca. 1600-1775
2
Revolution, 1979
2
-1922
1
-632
1
1526-1765
1
1632-1704
1
16th century
1
1783-1850
1
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