- End of the Irish potato famine
- Millard Fillmore succeeds Zachary Taylor as President of the United States of America
- The United States Republican Party is founded
- August 28 - Richard Wagner's opera Lohengrin premieres
- December 16 - The first four ships arrived at Lyttleton to settle Christchurch, New Zealand.
- August 5 - Guy de Maupassant, French writer
- August 25 - Charles Richet, Nobel Prize recipient for his work on anaphylaxis