Era
20th century
139
19th century
86
21st century
38
1564-1616
24
18th century
19
17th century
15
1945-
10
1989-
10
16th century
9
1878-1953
8
Early modern, 1500-1700
7
1936-1953
6
1812-1870
5
1912-1949
5
1933-1945
5
Civil War, 1861-1865
5
Revolution, 1775-1783
5
1860-1904
4
1979-
4
Colonial period, ca. 1600-1775
4
Republic, 1912-1949
4
1608-1674
3
1789-1900
3
1804-1864
3
1815-1861
3
1837-1901
3
1854-1900
3
1874-1940
3
1882-1941
3
1906-1989
3
1917-1936
3
1918-1945
3
1925-1953
3
1945-1989
3
1945-1990
3
1949-1976
3
1990-
3
1993-
3
1994-
3
20TH CENTURY
3
Cultural Revolution, 1966-1976
3
1743-1826
2
1750-1918
2
1757-1827
2
1764-1823
2
1775-1817
2
1783-1865
2
1828-1906
2
1849-1912
2
1863-1947
2
more ...