The real history of the 2nd Amendment, in practical terms, began when the American Minutemen fired back on British troops for the first time around 9 AM, April 19, 1775. It was hours after the Battle of Lexington (which was not much of a battle).
Sit down and watch this with your children and explain - the 2nd Amendment, and the right to keep and bear arms, was placed in the U.S. Constitution to help insure the American government would never become a tyrannical one. An armed citizenry is one of the checks and balances the Framers put in place.
Having recently toured Lexington and Concord the lesson of the first battle of the Revolutionary War is vivid in my mind. I hope it becomes the same in yours.