The taxation began in the 1760s, the Boston Massacre occurred in 1770, the Boston Tea Party in 1993 and the Battles of Lexington and Concord in April of 1775.
Patrick Henry's call to action, "Give me liberty or give me death," was the first strong public statement that, if we were to be free, if we were to have liberty, then we would have to fight Britain. Prior to Henry's speech to the gathering of Virginia delegates in Richmond, the prevailing belief was that we could negotiate with Britain.
Henry laid down the gauntlet and clearly presented his understanding of what we were facing.
Our choice was liberty or death.
Our founders chose to take the challenge and declared our Independence from Britain on July 4, 1776.
Our Declaration of Independence is a three-part document: the first a declaration of freedom, including our understanding of the natural order of authority and power; the second a long list of grievances, reinforcing the belief that there was no choice but to declare our independence as a free country; the third an acknowledgment of risk and the oath of the signers to one another.
The first section is the one that is most often quoted: "We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. -- That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, -- That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness."
The second part, less often referenced, lays out the reasoning for why we were seeking independence, a reasoning that included a long list of grievances against King George III.
Our founders concluded the document with the pledge to each other and an invocation of God. Knowing that their declaration would be seen as an act of treason by the king, the signers also knew that, if they were not successful, they would risk losing their lives.
This document declared us free, outlined the foundational understanding of our rights, from whom they came, and our responsibilities to maintain them.