Era
20th century
40
19th century
18
Civil War, 1861-1865
14
21st century
11
1963-2005
3
Revolution, 1775-1783
3
War of 1812
3
1821-1912
2
18th century
2
1936-
2
1948-
2
2009-
2
11th century
1
17th century
1
1802-1887
1
1805-1881
1
1819-1892
1
1820-1910
1
1832-1919
1
1833-1906
1
1880-1936
1
1880-1959
1
1882-1933
1
1896-1947
1
1913-2002
1
1920-2005
1
1926-1984
1
1926-2016
1
1938-2005
1
1946-
1
1947-
1
1949-
1
1949-1976
1
1951-
1
1958-
1
1959-1990
1
1959-2022
1
1960-
1
1964-
1
1980-2020
1
2011-
1
Appropriations and expenditures, 2011-2016
1
Civil War, 2011-
1
German occupation, 1914-1918
1
German occupation, 1940-1945
1
Middle Ages, 600-1500
1
To 1500
1
To 1876
1
Vietnam War, 1961-1975
1
War of 1912-1913
1
more ...