Era
20th century
28
20th century --
25
19th century --
13
1945-
7
18th century
6
19th century
6
17th century --
4
18th century --
4
1500-1700
2
16th century --
2
1720-1788
2
1745-1746
2
1775-1783
2
1783-1865
2
17th century
2
1990-
2
21st century
2
21st century --
2
Civil War, 1936-1939
2
Republic, 1912-1949
2
1268-1492
1
1492-1559
1
1532?-1588
1
1533-1603
1
1543-1634
1
1603-1649
1
1734-1784
1
1743-1826
1
1744-1797
1
1756-1842
1
1788-1900
1
1789-1900
1
1800-1883
1
1808-1877
1
1815-1861
1
1831-1870
1
1848-1950
1
1861-1865
1
1863-1877
1
1865-
1
1865-1877
1
1865-1898
1
1866-1895
1
1866-1895 --
1
1867-1910
1
1869-1948
1
1871-1918
1
1877-1964
1
1887-1920
1
1887-1972
1
more ...