In either;

1776 when the U.S. declared its independence and signed the Declaration of Independence.
1783 with the signing of the Treaty of Paris which officially ended the American Revolution and Great Britain recognized the United States' independence.

The ratification of the Constitution was complete on March 4, 1789, when New Hampshire adopted it, officially the United States didn't become "united" until all states accepted the Constitution.

It all depends on who you ask some people link that it was when the U.S. declared its independence and signed the Declaration of Independence, or 1783 with the signing of the Treaty of Paris which officially ended the American Revolution and Great Britain recognized the United States' independence. Some think that it is when the articles where written and some think that it was are current constitution was made.

PAUL REVERE’S MIDNIGHT RIDE WAS IN 1775…

TECHNICALLY, THE COLONIES WERE SETTLED BY THE ENGLISH…WHO ARE ‘THE BRITISH’. 

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