What do these numbers refer to?Give situations 1835 1856 1842 1850 1861 1857 1865 1858 Помгите плиз дам 35 Балов

one thousand eight hundred thirty five-1835one thousand eight hundred fifty six-1856thousand eight hundred fifty-1850one thousand eight hundred forty two-1842one thousand eight hundred fifty seven-1857one thousand eight hundred fifty eight-1858one thousand eight hundred sixty one-1861one thousand eight hundred sixty five-1865