Era
20th century
1,707
19th century
1,015
Civil War, 1861-1865
345
1900-1999
300
Revolution, 1775-1783
298
1933-1945
273
1945-
221
18th century
203
1900 - 1999
180
1800-1899
156
Colonial period, ca. 1600-1775
127
1775-1783
126
1945-1953
124
1861-1865
119
1961 - 1975
112
Since 1945
112
1945-1989
106
1918-1945
100
1783-1865
88
To 1775
86
1815-1861
82
1865-1918
82
1775-1865
81
1800 - 1899
74
1913-1921
70
To 1865
65
1953-1961
57
21st century
55
1858-1919
52
1856-1924
48
1865-1898
46
1882-1945
45
1929
45
1775 - 1783
42
1939-1945
42
1809-1865
41
1861 - 1865
40
1963-1969
39
1933 - 1945
36
1743-1826
35
1989-
35
17th century
34
1929-1933
33
1939 - 1945
33
1789-1809
32
1961-1963
32
1829-1837
31
1800-1999
30
1960-1980
30
1783-1809
28
more ...