Era
19th century
15
18th century
14
20th century
14
Revolution, 1775-1783
14
Colonial period, ca. 1600-1775
12
Ordovician
10
Devonian
8
To 1775
8
1732-1799
6
1775-1865
5
Cambrian
5
Civil War, 1861-1865
5
Silurian
5
1706-1790
4
Cretaceous
4
Mississippian
4
Precambrian
4
1775-1783
3
Pennsylvanian
3
Permian
3
-2014
2
1644-1718
2
1731-1802
2
1761-1849
2
1872-1951
2
1883-1935
2
1890-1969
2
Paleozoic
2
-2003
1
1660-1714
1
1674-1751
1
1697-1784
1
1720?-1782
1
1728-1786
1
1730-1802
1
1731-1803
1
1732-1808
1
1734-1807
1
1736-1799
1
1737-1801
1
1748-1789
1
1750-1831
1
1759-1839
1
1766-1842
1
1783-1809
1
1789-1793
1
1789-1797
1
1789-1846
1
1790-1834
1
1797-1801
1
more ...