Historical Period
20th century
31
1975-
7
To 1964
7
1868-1963
6
19th century
5
1865-1918
3
1960-1980
3
1963-1969
3
1980-
3
1980-2020
3
21st century
3
1925-2003
2
1933-1945
2
1945-
2
2001-2009
2
1852-1926
1
1865-1933
1
1877-1964
1
1900-1999
1
1915-1979
1
1915-1979,
1
1920-2000
1
1925-1990
1
1929-1968
1
1946-
1
1961-1969
1
1964-1975
1
1971-
1
Vietnam War, 1961-1975
1