Era
20th century
1,015
19th century
832
Civil War, 1861-1865
389
1900-1999
284
1775-1865
282
1800-1899
204
1865-
175
1951-
153
1865-1950
134
1865-1877
119
1897-1962
82
18th century
77
Colonial period, ca. 1600-1775
73
1865-1951
70
Since 1865
60
1861-1865
58
1905-1989
51
Revolution, 1775-1783
50
1909-2001
44
21st century
44
1865-1945
43
1945-
43
1863-1877
39
1800-1999
37
1877-1964
35
1918-
30
1775-1899
29
Since 1951
29
To 1964
27
1916-1990
24
17th century
22
16th century
20
1899-1979
20
1700-1899
18
1865-1918
18
2000-2099
18
To 1775
18
1815-1861
16
1809-1865
15
1800 - 1899
14
1900 - 1999
14
1911-1983
14
1929-1968
14
1945-1989
14
1600-1775
13
1857-1861
13
1895-1981
12
approximately 1500-1542
12
1767-1845
11
1903-1987
11
more ...