Era
20th century
77
To 1775
30
1945-1970
26
19th century
24
1971-
23
1865-1918
19
1783-1865
15
1918-1945
12
1945-
8
21st century
8
Colonial period, ca. 1600-1775
7
18th century
6
1933-1945
5
1945-1989
5
1775-1783
4
1929
4
Revolution, 1775-1783
4
To 1865
4
1815-1861
3
1970-
3
1980-2020
3
1783-1809
2
17th century
2
1835-1910
2
1865-1898
2
1919-1933
2
Civil War, 1861-1865
2
16th century
1
1702-1782
1
1737-1832
1
1775-1865
1
1836-1910
1
1842-1913
1
1849-1877
1
1856-1924
1
1858-1919
1
1869-1937
1
1874-1944
1
1879-1973
1
1882-1945
1
1894-1978
1
1908-1957
1
1908-2004
1
1909-1955
1
1917-2007
1
1923-
1
1932-1997
1
1934-1997
1
1934-2019
1
1938-
1
more ...