Era
20th century
283
21st century
118
19th century
84
2009-
68
1564-1616
52
1876-1950
46
1991-
40
Quaternary
40
1951-
36
18th century
34
Cretaceous
34
2001-2009
30
1945-
27
1989-
27
To 1500
27
2001-
25
1946-
22
1981-2001
22
2003-
22
2000-
21
Civil War, 1861-1865
21
16th century
20
1956-
20
17th century
19
1990-
18
1889-1951
17
1954-
17
1993-
17
1948-
15
Civil War, 2011-
15
Tertiary
15
1896-1980
13
1960-
13
Holocene
13
Revolution, 1910-1920
13
1942-
12
1944-
12
1952-
12
1958-
12
1980-
12
Revolution, 1775-1783
12
1882-1941
11
1947-
11
1957-
11
1964-
11
1965-
11
1986-
11
1809-1865
10
1949-
10
1724-1804
9
more ...