In past history, generals and political leaders alike, when seizing power the first thing they do is seize the weapons of the population. From Rome, to Germany, and modern day Venezuela, the key to smooth pacification is to take the weaponry from the local population.
In 1774-5 there was growing unrest in American colonies, and so good King George sent troops to Boston to help calm things down. People had grown discontent with their government. Increased taxes. incidences of violence, and growing protests were becoming common. The feeling was that with British troops garrisoned in Boston (and in other cities) things would ease tensions.
Upon arriving in Boston, General Gage had learned that the colonists had been alerted to their presence by a local militia group, the Minutemen, who arguably, were a threat to the troop’s safety. Gage ordered his troop to secure the city of Boston. When he did that, he did not secure the port, nor the utilities, not even the printing press. His first action was to capture the armories of the colonists by marching on them at Lexington and Concord.
His first act was to seize the guns.
At Lexington, only 77 men faced the oncoming 700 British forces, barely fielding one company of men. Most of them were farmers and shop owners, a few were in there mid 50’s—elderly by colonial standards.
But they were armed, warned by Paul Revere’s run.
They met for the first time at the village green, the equivalent of our downtown and shots were fired. The British were caught off guard; no American had ever fired on troops of the crown, but several of the Minutemen were shot and killed and fled the green. Further on at Concord, the Minutemen were able to muster a few hundred men, and engaged several companies of the British and defeated them, forcing them to retreat back to Boston. Casualties were few. When they managed to get back to the safety of Boston, General Gage did not order martial law.
He ordered the town leaders to surrender their weapons. The result was not an orderly seizure but open rebellion and the Minutemen’s numbers swelled to over 2,000. 
Indeed, most of what the caused the Revolutionary War to begin, was the British seizure of arms and powder in 1774-1775, and the blood spilled to protect those rights. The king additionally ordered all powder and arms to be taxed and was not allowed to be imported into America (see Powder Alarm). As a result, many colonists stashed their weapons, and buried brass cannon—the WMD’s of that period. While taxation without representation was a cause for a Revolution, it was when the crown attempted to take away our guns through taxation, regulation and eventual seizure, which caused Americans to take up the mantle of rebellion.
Our Founders and those Minutemen paid for the right to keep and bear arms with their lives and codified them into law. Those men recognized this and so to enable a potential for revolution as a safeguard against a tyrannical government they empowered states to keep sovereignty over their national guards, and protected a right to keep and bear arms second only to the freedom of speech. The Second Amendment is deliberately broad for a reason- there was to be no restriction on the ownership and use of weapons by the population to act as deterrent to the forces of tyranny. If the government had no control on personal weapons, then it dare not move too aggressively against its own people. It did not matter if the population could field an effective fighting force, the mere existence of mass weaponry would deter any energetic government movement. The right to bear arms is God-given right, for it is the right to defend oneself from an enemy no matter its source, and it is codified into our law through our Constitution. It is not for us to debate that wisdom as this late date.
Ralph Waldo Emerson said it best, in poem from 1835, called the Concord Hymn:
By the rude bridge that arched the flood,
Their flag to April’s breeze unfurled,
Here once the embattled farmers stood,
And fired the shot heard round the world….
…Spirit, that made those spirits dare,
To die, and leave their children free,
Bid Time and Nature gently spare
The shaft we raise to them and thee.
Those men believed in spilling blood before allowing the government to take their weapons away.
What are you doing to prevent it today?
