20th century 10,835 View Records 19th century 5,169 View Records 21st century 2,713 View Records 18th century 1,580 View Records 1564-1616 1,015 View Records Civil War, 1861-1865 986 View Records 17th century 968 View Records 1945- 886 View Records Cretaceous 838 View Records 1945-1989 741 View Records 16th century 589 View Records 1933-1945 551 View Records Revolution, 1775-1783 517 View Records 1946- 492 View Records 1989- 483 View Records Tertiary 446 View Records To 1500 441 View Records Quaternary 415 View Records 2009- 408 View Records 2001-2009 389 View Records Early modern, 1500-1700 383 View Records Colonial period, ca. 1600-1775 370 View Records 1991- 349 View Records Precambrian 346 View Records Paleozoic 334 View Records Cenozoic 293 View Records 1960- 279 View Records 1951- 272 View Records 2000- 261 View Records 1929 250 View Records Permian 249 View Records 1809-1865 239 View Records Eocene 235 View Records 1918-1945 225 View Records 1993-2001 223 View Records Jurassic 223 View Records Mesozoic 216 View Records 1981-2001 213 View Records 1949- 210 View Records Pennsylvanian 206 View Records Miocene 201 View Records 1947- 195 View Records Pleistocene 193 View Records 1948- 191 View Records Ordovician 189 View Records 1961-1970 187 View Records Devonian 174 View Records 1979- 170 View Records 1945-1953 168 View Records 1991-2000 168 View Records 1950- 167 View Records 1608-1674 165 View Records 1882-1945 165 View Records -1400 164 View Records 1917-1963 164 View Records Mississippian 164 View Records 1980- 162 View Records 1882-1941 160 View Records 1952- 158 View Records 1990- 154 View Records 1783-1865 148 View Records 1953-1961 148 View Records 1969- 148 View Records Triassic 148 View Records 1970- 147 View Records 1965- 144 View Records 1959- 139 View Records 1812-1870 137 View Records 1954- 136 View Records Civil War, 2011- 136 View Records 1981-1989 135 View Records 2001- 133 View Records 1993- 130 View Records Middle English, 1100-1500 130 View Records 1866-1895 127 View Records 1724-1804 125 View Records 1956- 125 View Records 1913-1994 124 View Records To 1775 124 View Records 1897-1962 123 View Records Cambrian 123 View Records 1958- 120 View Records 1819-1891 118 View Records 1951-1960 118 View Records World War, 1939-1945 118 View Records 1775-1865 117 View Records 2003- 117 View Records Revolution, 1789-1799 117 View Records 1975- 116 View Records 1997- 116 View Records 1775-1783 115 View Records 1961- 115 View Records Holocene 115 View Records Pliocene 114 View Records 1743-1826 113 View Records 1942- 113 View Records 1941- 112 View Records 1960-1980 112 View Records 1843-1916 110 View Records 1964- 110 View Records