Lexington and Concord was the first battle of the war, but let's not go so far to make the mistake that it was the spark that ignited the war. The war would have occurred regardless.
Although a bit off topic, the war was won by the US only after Washington forged an effective, organized regular army. A militia did not and would not have won the war. The symbol of public spirited minute men standing up against the power of the government to defeat it is a myth. Yet, the paranoid low IQ militia types today continue to believe that they are the bulwarks protecting society against the power of the government, just like they did back in 1776.
without quibbling about the importance of the facts you mention here, it's just the wrong idea to minimize the necessity of common support for Washington. His American boys were part-timers trying to keep the work on their home/family needs up, and their support varied hugely with the fortunes of war, victories sometimes unexpected and unexplainable with attribution to "God", or huge military mistakes by the British.
It is further improbable that the revolution would have been won without the French alliance, and maybe even the Russians, and a Prussian military genius who took the trouble to train the American troops.
I agree that no effective power resides in ignorant yahoos without good leadership, and the moral righteousness of high principles that prevent soldiers from committing atrocities that would destroy popular support.
Having a meaningful democracy with peoples votes as the chief determinant is the best way forward anytime.