Era
20th century
143
21st century
60
1900-1999
55
19th century
45
Civil War, 1861-1865
31
2000-2099
26
17th century
19
1989-
19
18th century
16
1780-1831
13
1800-1899
13
Revolution, 1775-1783
13
1939-1945
10
To 1500
10
2001-2009
9
Civil War, 1642-1649
9
Since 1989
9
1724-1804
8
1918-1945
8
French and Indian War, 1754-1763
8
1775-1783
7
1945-
7
1945-1989
7
2003-2011
7
1754-1763
6
1800-1999
6
1914-1918
6
1492-1648
5
1700-1799
5
1744-1748
5
1809-1865
5
1900-2099
5
1933-1945
5
King George's War, 1744-1748
5
Middle Ages, 600-1500
5
16th century
4
1750-1918
4
1961-2011
4
600-1500
4
Revolution, 1789-1799
4
To 1900
4
-1536
3
1225?-1274
3
1602-1662
3
1605-1660
3
1648-1789
3
1703-1764
3
1747
3
1775
3
1828-1910
3
more ...