On this day in 1776, in Philadelphia, the Second Continental Congress declared that the thirteen colonies which they represent would no longer be ruled by Great Britain and her king, setting forth the reasons why they would no longer swear allegiance thereto, and assume a "separate and equal station" among the nations of the earth. Among other things, this Declaration of Independence set forth the then-radical idea that all men are created equal, and have rights which come directly from their Creator. This was a departure from the centuries-old European tradition be people being born into their respective ranks, each with its own prerogatives, distinct from the other ranks. Telling a king that he was equal to a peasant was something you just didn't do back then without consequences.
Here are some related articles:
From Hot Air, "Happy Independence Day 2017".
From National Review, "A People without a King".
From Townhall, "5 Ways the American Revolution Was Different From Other Revolutions".
From FrontpageMag, "Freedom and Tyranny: The Meaning of Independence Day".
And of course, you can also read the original document.