Era
20th century
172
19th century
52
21st century
36
Civil War, 1861-1865
22
1929
21
Revolution, 1775-1783
13
18th century
11
Colonial period, ca. 1600-1775
11
1867-1957
9
1929-1968
8
1822-1913
7
1732-1799
6
1933-1945
6
2008
6
1775-1865
5
1853-1890
5
1902-1967
5
1917-2000
5
1988
5
2011
5
Bombardment, 1945
5
German occupation, 1940-1945
5
1809-1865
4
1864?-1943
4
1886-1957
4
1913-2005
4
1919-1972
4
1986
4
2009
4
Heian period, 794-1185
4
1564-1616
3
1564-1642
3
1642-1727
3
1706-1790
3
1799-1883
3
17th century
3
1809-1852
3
1815 or 1816-
3
1818-1895
3
1832-1888
3
1840-1926
3
1867-1912
3
1871-1948
3
1882-1956
3
1898-1951
3
1929-1945
3
1941-
3
1941-1955
3
1942-
3
1949-
3
more ...