- 1776 US Congress proclaims the Declaration of Independence and independence from Britain
- 1785 James Hutton, geologist, publicly reads an abstract of his theory of uniformitarianism for the first time at the meeting of the Royal Society of Edinburgh
- 1803 The Louisiana Purchase is announced to the American people
- 1838 Huskar Colliery Mining Disaster in Silkstone England: mining pit floods drown 26 children, leads to 1842 'Mines and Collieries Act' bans women and children working underground
- 1934 Hungarian physicist Leo Szilard patents the chain-reaction design for the atomic bomb.
Howard Florey and Norman Heatley meet for 1st time, 11 days later they successfully recreate penicillin
On July 4, 1941