Era
prev ...
1933-1945
1
1936
1
1938-
1
1938-1991
1
1945-1989
1
1946-
2
1951-
4
1960
1
1963-
1
1974-
1
1974-1977
1
1976
3
1978
2
1979
2
1980
2
1981
2
1982
2
1984
2
1985
1
1986
3
19th century
3
2016
1
2017-2021
1
20e siècle
1
20th century
6
21e siècle
1
21st century
2
Civil War, 1861-1865
1
Colonial period, ca. 1600-1775
4
Pennsylvania, 1976
1
Revolutionary War
1
Since 1900
1
To 1775
6
To 1950
1