Era
19th century
151
1865-1950
134
1951-
126
20th century
90
1775-1865
81
Civil War, 1861-1865
78
1865-1877
69
1800-1899
30
Since 1951
28
1865-
27
1861-1865
17
1857-1861
13
1815-1861
12
Since 1865
12
1865-1945
11
1900-1999
11
1800-1950
10
1865-1900
10
1945-
10
1945-1989
10
1775-1899
8
1933-1945
8
To 1775
8
1783-1865
7
1863-1877
7
21st century
7
To 1964
7
1767-1845
6
1800-1999
6
1865-1898
6
1865-1951
6
1918-
6
1989-
6
1789-1869
5
1809-1865
5
1849-1853
5
1865-1918
5
1865-1933
5
1877-1964
5
18th century
5
1794-1865
4
1845-1861
4
1861-1950
4
1865-1999
4
1908-1973
4
Since 1900
4
Since 1945
4
To 1865
4
1775-1950
3
1807-1864
3
more ...