Era
20th century
140
19th century
64
21st century
55
1946-
27
18th century
26
2009-
25
To 1500
24
Revolution, 1775-1783
22
1993-2001
20
Civil War, 1861-1865
20
2001-2009
19
1989-
15
1945-1989
14
1990-
14
1934-
13
1960-
12
17th century
11
1809-1865
11
1822-1903
11
1918-1961
11
1991-
11
1997-
11
1925-1963
10
1959-
10
1965-
10
2003-
10
Colonial period, ca. 1600-1775
10
1929
9
1948-
9
1959-1990
9
1783-1865
8
1929-1968
8
1964-
8
16th century
7
1822-1913
7
1947-
7
1947-2017
7
1949-
7
1970-
7
1984-
7
1986-
7
2001-
7
2002-
7
War of 1812
7
1735-1826
6
1890-1969
6
1936-2016
6
1945-
6
1969-
6
1588-1679
5
more ...