Era
2000
54
1981-2001
39
1990
35
1981-
26
2010
17
1945-
16
1990-
11
Civil War, 1861-1865
11
21st century
10
20th century
9
1960-
8
2001-2009
6
Since 1981
5
1949-
4
2000-
4
2002
4
2011
4
1970-
3
1971-1990
3
1981 - 2001
3
1987
3
2000-2099
3
Since 1990
3
1960-1980
2
1970
2
1970 - 2000
2
1980-1990
2
1992
2
1994
2
19th century
2
2001
2
2012
2
Since 1949
2
Since 1960
2
Since 2000
2
1800 - 1999
1
1821 - 1822
1
1821-1822
1
1861-1865
1
1895-1945
1
1900 - 1999
1
1900-2099
1
1918-
1
1918-1970
1
1945-1989
1
1947-
1
1968-
1
1968-1998
1
1969-
1
1970-2010
1
more ...