Era
1865-1950
213
20th century
197
1945-
155
To 1775
130
1951-
114
1966-1998
96
19th century
91
1775-1865
85
1865-
84
1900-1999
81
Colonial period, ca. 1600-1775
77
1946-
74
1775-1783
69
1945-1976
65
1974-
64
1991-
63
2009-
58
1976-
55
Since 1951
55
1976-2002
54
Revolution, 1775-1783
51
1861-1865
50
1976-1994
50
Since 1945
50
1986-
49
1966 - 1998
47
1789-1797
46
1980-
46
21st century
46
1933-1945
44
1947-
44
Civil War, 1861-1865
44
1935-
43
1945-1985
42
2002-
41
1809-1817
40
1970-
38
1994-
38
18th century
37
1960-
37
1961-1963
36
1975-
36
1829-1919
35
1949-
33
1958-
32
Since 1976
31
World War, 1914-1918
31
1789-1809
30
1868-
30
1966-
30
more ...