On this day in 1905, Albert Einstein sent the article On the Electrodynamics of Moving Bodies, in which he introduced special relativity, for publication in Annalen der Physik.
On this day in 1937, the world's first emergency telephone number was introduced in London. 999 remains the emergency number for the UK.
On this day in 1960, Congo gained independence from Belgium.
On this day in 1966, the National Organization for Women, the United States' largest feminist organization, was founded.