20th century 104
21st century 63
19th century 40
18th century 12
Civil War, 1861-1865 10
1945- 8
1564-1616 7
1946- 7
1991- 7
2009- 7
Revolution, 1775-1783 7
1988- 6
Civil War, 2011- 6
Mesozoic 6
17th century 5
1897-1962 5
Carboniferous 5
Colonial period, ca. 1600-1775 5
Early modern, 1500-1700 5
1817-1862 4
1819-1891 4
1899-1961 4
1980- 4
Cretaceous 4
Eocene 4
Paleozoic 4
Precambrian 4
Tertiary 4
World War, 1939-1945 4
1685-1750 3
1843-1916 3
1873-1947 3
1874-1963 3
1902-1995 3
1917-1963 3
1933-1945 3
1936-2016 3
1945-1989 3
1965- 3
1986- 3
1993- 3
1997- 3
2001-2009 3
2003- 3
Early modern and Elizabethan, 1500-1600 3
Quaternary 3
To 1900 3
1588-1679 2
1608-1674 2
1643-1687 2
1661?-1731 2
16th century 2
1812-1870 2
1863-1877 2
1874-1964 2
1878-1967 2
1884-1972 2
1900-1999 (20th century) 2
1902-1968 2
1906-1989 2
1911-1983 2
1913-2006 2
1926-2005 2
1933-2020 2
1935-1977 2
1945-1953 2
1945-1955 2
1958- 2
1961- 2
1967- 2
1971- 2
1972- 2
1989- 2
1990- 2
2000- 2
2001- 2
2011- 2
Cambrian 2
Civil War, 2015- 2
Confederation, 1783-1789 2
Constitutional period, 1789-1809 2
Devonian 2
Holocene 2
Jurassic 2
Middle English, 1100-1500 2
Neogene 2
Pleistocene 2
active 17th century 2
-1400 1
-1402 1
-1561 1
1478-1535 1
1508-1588 1
1533-1592 1
1547-1616 1
1562-1635 1
1585-1672 1
15th and 16th centuries 1
15th century 1
1613-1689 1