Era
20th century
287
Civil War, 1861-1865
247
19th century
236
1809-1865
68
18th century
57
1945-1989
54
2001-2009
44
1989-
43
Revolution, 1775-1783
42
Colonial period, ca. 1600-1775
39
1861-1865
35
1743-1826
34
21st century
32
1933-1945
31
1946-
30
1783-1865
29
1775-1783
27
1945-
24
1917-1963
21
1815-1861
18
1882-1945
18
1865-1918
17
1953-1961
17
1961-1963
17
1980-
16
1865-1950
15
1945-1953
15
1951-
15
To 1865
15
1963-1969
14
16th century
13
1706-1790
13
1775-1865
13
1890-1969
13
1918-1945
13
1783-1809
12
17th century
12
1908-1973
12
1969-1974
12
1884-1972
11
1981-1989
11
1989-1993
11
2009-
11
1868-1963
10
1924-
10
1975-
10
1993-2001
10
1877-1964
9
1960-1980
9
1783-1815
8
more ...