23rd January » The first bridge over the Mississippi River opens in what is now Minneapolis, Minnesota, a crossing made today by the Hennepin Avenue Bridge.
26th January » Point No Point Treaty is signed in Washington Territory.
28th January » A locomotive on the Panama Canal Railway, runs from the Atlantic Ocean to the Pacific Ocean for the first time.
11th February » Kassa Hailu is crowned Tewodros II, Emperor of Ethiopia, by Abuna Salama III in a ceremony at the church of Derasge Maryam
12th February » Michigan State University is established.
14th February » Texas is linked by telegraphy e.g telegraph to the rest of the United States, with the completion of a connection between New Orleans and Marshall, Texas.
2nd March » Alexander II of Russia or Alexander II becomes Tsar of Russia.
30th March » Origins of the American Civil War: Bleeding Kansas "Border Ruffians" from Missouri invade Kansas and force election of a pro-slavery legislature.
19th April » Visit of Napoleon III to Guildhall, London
3rd May » American adventurer William Walker (filibuster) called William Walker departs from San Francisco with about 60 men to conquer Nicaragua.
1st June » The United States e.g American adventurer William Walker (filibuster) called William Walker conquers Nicaragua.
2nd June » The Portland Rum Riot occurs in Portland, Maine.
4th June » Major Henry C. Wayne departs New York City New York aboard the USS Supply 1846 6 to procure camels to establish the U.S. Camel Corps.
1st July » Signing of the Quinault Treaty: The Quinault people named Quinault and the Quileute people e.g Quileute cede their land to the United States.
1st August » The first ascent of Monte Rosa, the second highest summit in the Alps.
3rd September » American Indian Wars: In Nebraska, 700 soldiers under United States General William S. Harney avenge the Grattan massacre by attacking a Sioux village and killing 100 men, women and children.
9th September » Crimean War: The Siege of Sevastopol (1854–55) called Siege of Sevastopol comes to an end when Russian forces abandon the city.
17th November » David Livingstone becomes the first European to see the Victoria Falls in what is now present-day Zambia-Zimbabwe.