The idea of a militia is very old. As long ago as 1181, the courts of the day recognized the average citizen's responsibility to keep and bear arms in defense of the Crown. The American militia tradition can be found in writings from England in 1581, where any man from the age of four to the age of 60, in various capacities, had a role to play in the security of the Kingdom.
The Colonial militias began during the early to mid-18th century. British colonists who were pushing the borders of the frontier were in constant danger of coming under Indian attacks. This column will not debate the reason for the violence but will focus on the Colonial response. In order to protect themselves, the colonists formed groups of citizens for defense. Every able-bodied man and older boys were expected to show up for drills on Sunday after church. Skipping these drills or showing up without your musket or rifle subjected you to a penalty. You were just as responsible for your neighbor’s safety as you were your own.
The point here is that these men brought their weapons with them to the town square. They did not have their guns issued to them by the local government nor were their weapons stored in an armory. Men owned their weapons and the powder and shot required to use them. When an alarm went up, they mustered and deployed to face the threat. When the danger was over, they went back to their homes with their guns and ammunition. They resumed their chores but remained vigilant for the next alarm.
With the coming of the French and Indian War, a war in which a young George Washington fought, militias gained an even greater importance by keeping the enemy at bay even while British armies engaged the enemy in major battles.
When the American Revolution began, many militias were sent by the several states to assist in the fight for liberty. Some militia acquitted themselves bravely, but General Washington was mostly unimpressed with their use as soldiers. They were difficult to control and could not be counted on in a battle. Washington is quoted as saying "...can any thing (the exigency of the case indeed may justify it), be more destructive to the recruiting service, than giving Ten dollars bounty for Six weeks service of the Militia, who come in, you can not tell how—go, you cannot tell when—and act, you cannot tell where—consume your provisions—exhaust your Stores, and leave you at last at a critical moment. These Sir, are the men, I am to depend upon, Ten days hence." Towards the end of the War for Independence, militia service improved somewhat but after all they were farmers, lawyers, blacksmiths, teachers, teamsters, builders, etc. They were not soldiers. They were average citizens charged with protecting their families and neighbors.
So now we come to examine the meaning of the words in the 2nd Amendment. Chiefly among those is the term “a well-regulated militia”. Well-regulated in the 18th century tended to be something like well-organized, well-armed, well-disciplined. It didn't mean 'regulation' in the sense that we use it now, in that it's not about the regulatory state. It means the militia was in an effective shape to fight. In other words, the state wasn’t controlling the militia, but rather the militia was prepared to do its duty. As we have shown, it was comprised of individual citizens.
So you should now be able to engage a gun-grabber in a debate as to what the 2nd Amendment is really about and what its framers intended. Encourage them to find a few books about the American History and discover for themselves what it means to be an American.