Era
20th century
544
19th century
176
21st century
74
Civil War, 1861-1865
72
1929-1968
41
18th century
32
Revolution, 1775-1783
32
To 1863
29
1818-1895
26
1877-1964
26
1863-1877
25
1929
21
To 1964
20
1901-1953
16
1902-1967
15
1919-1972
15
1868-1963
13
1951-
13
1975-
13
1964-
12
Colonial period, ca. 1600-1775
12
1822-1913
11
1961-1969
11
1908-1993
10
1925-1965
10
1964-1975
10
1775-1865
9
1809-1865
9
1908-1960
9
1945-1989
9
1865-1877
8
1913-2005
8
1924-1987
8
1918-1961
7
1944-
7
1799-1883
6
1941-1955
6
1743-1826
5
1835-1910
5
1856-1915
5
1864?-1943
5
1865-1950
5
1887-1940
5
1940-2020
5
1948-
5
1732-1799
4
1783-1865
4
17th century
4
1847-1944
4
1861-1865
4
more ...