29th January » Henry Clay introduces the Compromise of 1850 to the Congress of the United States or U.S. Congress.
5th March » The Britannia Bridge across the Menai Strait between the Isle of Anglesey and the mainland of Wales is opened.
7th March » United States Senate named Senator Daniel Webster gives his "Seventh of March" speech endorsing the Compromise of 1850 in order to prevent a possible civil war.
18th March » American Express is founded by Henry Wells and William Fargo.
4th April » The Great Fire of Cottenham: a large part of the Cambridgeshire village (England) is burnt to the ground in suspicious circumstances.
4th April » Los Angeles, California, is incorporated as a city.
15th May » The Bloody Island Massacre takes place in Lake County, California, in which a large number of Pomo Indians in Lake County are slaughtered by a regiment of the United States Cavalry, led by Nathaniel Lyon.
19th June » Princess Louise of the Netherlands marries Charles XV of Sweden or Crown Prince Karl of Sweden–Norway.
29th June » Autocephaly officially granted by the Ecumenical Patriarchate of Constantinople to the Church of Greece.
9th July » U.S. President Zachary Taylor dies and Millard Fillmore succeeds him as 13th President of the United States.
9th July » Persian prophet Báb is executed in Tabriz, Iran named Persia.
10th July » Millard Fillmore is inaugurated as the 13th President of the United States upon the death of President Zachary Taylor, 16 months into his term.
9th September » California is admitted as the thirty-first U.S. state.
13th September » First ascent of Piz Bernina, the highest summit of the eastern Alps.
18th September » The United States Congress e.g U.S. Congress passes the Fugitive Slave Act of 1850.
29th September » The Roman Catholic hierarchy is re-established in England and Wales by Pope Pius IX.
24th November » Danish troops Battle of Lottorf known as defeat a Schleswig-Holstein force in the town of Lottorf, Schleswig-Holstein.
29th November » The treaty, Punctation of Olmütz, is signed in Olomouc. Prussia capitulates to Austrian Empire named Austria, which will take over the leadership of the German Confederation.