Era
20th century
171
1900-1999
70
21st century
38
To 1500
38
19th century
25
Civil War, 1861-1865
22
Medieval, 500-1500
15
18th century
13
1933-1945
13
1945-
13
2000-2099
12
Since 1900
12
1918-1945
10
16th century
8
17th century
8
1945-1989
8
1989-
8
1900-2099
7
1939-1945
7
1789-1815
6
1800-1899
6
1648-1789
5
1700-1799
5
1990-
5
To 146 B.C.
5
1328-1589
4
1485-1603
4
1861-1865
4
1889-1945
4
2001-2009
4
Civil War, 1983-2009
4
Since 1945
4
1603-1714
3
1800-1999
3
1871-1918
3
1899-1961
3
1900 - 1999
3
1914-1918
3
1917-1945
3
1971-
3
1978-
3
1979-1991
3
1980-
3
1992-
3
2003-2011
3
510-30 B.C.
3
Civil War, 1975-1990
3
Eighty Years' War, 1568-1648
3
Middle Ages, 600-1500
3
Since 1991
3
more ...