Era
1600-1775
1
1775-1865
3
1783-1865
3
1783-1933
1
1800-1918
1
1849-1877
1
1857-1861
2
1860
1
1865-
6
1865-1877
2
1865-1900
2
1865-1918
3
1865-1933
2
1865-1945
3
1865-1950
5
1865-1951
3
1900-1999
1
1918-
6
1945-
10
1945-1989
1
1951-
10
1989-
1
19th century
6
20th century
2
Civil War, 1861-1865
1
Colonial period, ca. 1600-1775
1
John Brown's Raid, 1859
1
Since 1865
4
Since 1945
3
To 1865
1