Era
1860
56
1856
35
1861
28
1850
27
1862
27
1857-1861
25
1863
21
1857
18
1851
17
1859
17
1861-1865
17
1836
16
1854
16
1845
15
1855
15
1852
14
1837
13
1839
13
1854-1861
13
1853-1857
11
1847
10
1858
10
1792-1868
9
1849-1861
9
Civil War, 1861-1865
9
1775-1865
8
1840
8
1833
7
1838
7
1773
6
1846
6
1848
6
1780-1842
5
1845-1849
5
1849-1853
5
1853
5
1864
5
John Brown's Raid, 1859
5
1782-1852
4
1804-1876
4
1824
4
1832
4
1834
4
1835
4
1841
4
Civil War
4
Controversial literature, 1854
4
To 1865
4
1777-1852
3
1780-1852
3
more ...