Wikipedia:Selected anniversaries/June 18
- 1812 - The United States declared war against the United Kingdom, officially beginning the War of 1812.
- 1815 - Napoléon Bonaparte fought and lost his final battle, the Battle of Waterloo.
- 1858 - Charles Darwin received a manuscript by Alfred Russel Wallace (pictured) on evolution, which prompted him to publish his theory.
- 1940 - World War II: Charles de Gaulle, leader of the Free French Forces, made an appeal to the French people following the fall of France to Nazi Germany, rallying them to support the Resistance.
- 1979 - The United States and the Soviet Union signed the SALT II treaty, placing specific limits on each side's stock of nuclear weapons.