- February 11 - US House unanimously passes resolution guaranteeing noninterference with slavery in any state.
- April 12 - United States Civil War begins at Fort Sumter, South Carolina
- Abraham Lincoln succeeds James Buchanan as President of the United States of America
- Kansas becomes 34th state in the United States
- Victor Emmanuel becomes first king of Italy
- Change of emperor of the Ottoman Empire from Abd-ul-Mejid (1839-1861) to Abd-ul-Aziz (1861-1876)
- Sir William Crookes discovers Thallium (see Discovery of the chemical elements)