The British Army were ordered to collect and destroy firearms and other supplies stored by the militia in Concord, Mass. Long story short, the Militia fought back, and defeated three companies of British Army regulars at Concord, and then some.
The "Shot Heard 'Round the World," was fired in Lexington, though the exact story is unknown, with both sides having coming up with different version of what happened.
Most would agree that when the British regulars came into Lexington, on the morning of April 19, 1775, Lexington militiamen, who had been warned of what the Brits were coming to do, came out of a local tavern into the common to watch the regulars, along with a few dozen other locals.
The leader of the militia was Captain John Parker. Below is what he swore to after the fight:
I ... ordered our Militia to meet on the Common in said Lexington to consult what to do, and concluded not to be discovered, nor meddle or make with said Regular Troops (if they should approach) unless they should insult or molest us; and, upon their sudden Approach, I immediately ordered our Militia to disperse, and not to fire:—Immediately said Troops made their appearance and rushed furiously, fired upon, and killed eight of our Party without receiving any Provocation therefor from us.
The leader of the British regulars was Lieutenant William Sutherland. Sutherland reportedly called out, "lay down your arms, you damned rebels!"
Well, they certainly didn't, and someone fired a shot, and all hell broke loose.
Wikipedia - "The Shot Heard 'Round The World"
Wikipedia - The Battles of Lexington and Concord
"Odd Angry Shot: Pause and Remember the 19th of April, 1775," Guns Magazine, April 2010, by John Connor.
Historians tell us only about 3 percent of colonials actively fought as patriots in the Revolution, supported by about 1/3 of the population. One-third sat it out, remaining neutral. Another 1/3 were British loyalists, and in fact, toward the end of the war, more loyalists were fighting for King George and revolutionaries were fighting for their new nation. Against all odds, the 3-percenters prevailed.More on Three Percenters
Sometimes great deeds are done by the few, the committed. This 19th of April, let us remember those few, those brave, those 3-percenters.