Era
20th century
1,104
19th century
318
21st century
113
1945-
96
18th century
91
Revolution, 1775-1783
73
Civil War, 1861-1865
62
1945-1989
47
Colonial period, ca. 1600-1775
40
1933-1945
37
1961-1969
37
1960-1980
35
1989-
32
1783-1865
25
1945-1953
24
17th century
21
1775-1783
20
1865-1918
19
To 1865
18
1815-1861
17
War of 1812
15
1946-
14
Revolution
14
1918-1945
13
1953-1961
13
1963-1969
13
1843-1916
12
1929
12
1961-1963
12
1980-
12
1919-1933
10
2001-
10
1830-1886
9
1865-1898
9
1913-1921
9
1929-1968
9
1969-
9
1993-
9
1865-
8
1945-1975
8
1970-
8
1849-1877
7
1945-1970
7
2001-2009
7
2016
7
To 1775
7
1775-1865
6
1819-1891
6
1868-1963
6
1884-1972
6
more ...