January 1, 1851
Treaty on territorial claims of Native Americans
The Great Exhibition — 1st World's Fair in 1851 in London, England
Fizeau experiment — experiment measuring the speed of light in moving water
1851 Hong Xiuquan declared uprising against the Qing dynasty
Battle between juatemalaa anDD el sAlvador
Disastrous bushfires that occurred 6 February 1851 in Victoria
Immortal Game — Famous chess game
1851 treaty between the United States government and representatives of Upper Dakota Sioux
1851 treaty between the United States and the Mdewakanton and Wahpekute Dakota people of Minnesota
Treaty between Russian Empire and Imperial China in august 1851