Era
20th century
138
19th century
94
1900-1999
51
21st century
45
1800-1899
27
18th century
27
1980-
23
2000-2099
22
17th century
20
Since 1900
15
1989-
14
Civil War, 1861-1865
13
1945-1989
11
1968-1998
11
1998-
11
Colonial period, ca. 1600-1775
11
1945-
9
1969-
7
1991-
7
16th century
6
1865-1877
6
1865-1950
6
1947-
6
1960-
6
To 1500
6
1600-1799
5
1918-1945
5
1421-1737
4
1600-1699
4
1800-1999
4
1900-2099
4
1917-1936
4
1948-
4
1960-1980
4
Since 1945
4
Since 1980
4
To 1421
4
To 1865
4
1588-1679
3
1756-1836
3
1771-1810
3
1789-1851
3
1809-1849
3
1865-1918
3
1870-1924
3
1870-1940
3
1871-1918
3
1933-1945
3
1945-1953
3
1945-1985
3
more ...