The American Revolutionary War began this year, with the first military engagement on April 19 Battles of Lexington and Concord on the day after Paul Revere's ride.
The Second Continental Congress took various steps toward organizing an American government, appointing George Washington commander-in-chief (June 14), Benjamin Franklin postmaster general (July 26) and creating a Continental Navy (October 13) and a Marine force (November 10) as landing troops for it, but as yet the 13 colonies have not declared independence, and both the British (June 12) and American (July 15) governments make laws.
On July 6, Congress issues the Declaration of the Causes and Necessity of Taking Up Arms and on August 23, King George III of Great Britain declares the American colonies in rebellion, announcing it to Parliament on November 10.
Human knowledge and mastery over nature advanced when James Watt built a successful prototype of a steam engine, and a scientific expedition continued as Captain James Cook claims the South Georgia and South Sandwich Islands in the south Atlantic Ocean for Britain.
Nature's power over humanity is dramatically demonstrated when the Independence Hurricane (August 29 – September 13) devastates the east coast of North America, killing 4,173, and a smallpox epidemic begins in New England.