The Second Amendment is about a well regulated militia. Those are actually the first for words and the reasoning for the right to keep and bear arms.
Much argument could have been cleared up if the 2nd Amendment said something like this:
1. "Since a well regulated Militia is necessary to the security of a free State, the right of the people to keep and bear Arms while serving in a Militia shall not be infringed."
or this:
2. "A well regulated Militia is necessary to the security of a free State. Regardless, the right of the people to keep and bear Arms shall not be infringed."
The Supreme Court has taken (2) as being the meaning, not (1).
Not that the Supreme Court is always right in everyone's opinion, and many have argued that (1) is the correct meaning, but (2) how the law interprets it.
The founding fathers did think that militias were useful. They also thought that armed citizens in general are a vital protection against government tyranny.
Here are some of their own words on that:
“No free man shall ever be debarred the use of arms.” – Thomas Jefferson, Virginia Constitution, Draft 1, 1776
“The Constitution of most of our states (and of the United States) assert that all power is inherent in the people; that they may exercise it by themselves; that it is their right and duty to be at all times armed.” – Thomas Jefferson, letter to John Cartwright, 5 June 1824
“To disarm the people… the most effectual way to enslave them.” – George Mason, referencing advice given to the British Parliament by Pennsylvania governor Sir William Keith, The Debates in the Several State Conventions on the Adooption of the Federal Constitution, June 14, 1788
“Before a standing army can rule, the people must be disarmed, as they are in almost every country in Europe. The supreme power in America cannot enforce unjust laws by the sword; because the whole body of the people are armed, and constitute a force superior to any band of regular troops.” – Noah Webster, An Examination of the Leading Principles of the Federal Constitution, October 10, 1787
“To preserve liberty, it is essential that the whole body of the people always possess arms, and be taught alike, especially when young, how to use them.” – Richard Henry Lee, Federal Farmer No. 18, January 25, 1788
“Guard with jealous attention the public liberty. Suspect everyone who approaches that jewel. Unfortunately, nothing will preserve it but downright force. Whenever you give up that force, you are ruined…. The great object is that every man be armed. Everyone who is able might have a gun.” – Patrick Henry, Speech to the Virginia Ratifying Convention, June 5, 1778
“This may be considered as the true palladium of liberty…. The right of self defense is the first law of nature: in most governments it has been the study of rulers to confine this right within the narrowest limits possible. Wherever standing armies are kept up, and the right of the people to keep and bear arms is, under any color or pretext whatsoever, prohibited, liberty, if not already annihilated, is on the brink of destruction.” – St. George Tucker, Blackstone’s Commentaries on the Laws of England, 1803
“The Constitution shall never be construed to prevent the people of the United States who are peaceable citizens from keeping their own arms.” – Samuel Adams, Massachusetts Ratifying Convention, 1788
“The right of the citizens to keep and bear arms has justly been considered, as the palladium of the liberties of a republic; since it offers a strong moral check against the usurpation and arbitrary power of rulers; and will generally, even if these are successful in the first instance, enable the people to resist and triumph over them.” – Joseph Story, Commentaries on the Constitution of the United States, 1833
“
f circumstances should at any time oblige the government to form an army of any magnitude that army can never be formidable to the liberties of the people while there is a large body of citizens, little, if at all, inferior to them in discipline and the use of arms, who stand ready to defend their own rights and those of their fellow-citizens. This appears to me the only substitute that can be devised for a standing army, and the best possible security against it, if it should exist.” – Alexander Hamilton, Federalist No. 28, January 10, 1788
“As civil rulers, not having their duty to the people before them, may attempt to tyrannize, and as the military forces which must be occasionally raised to defend our country, might pervert their power to the injury of their fellow citizens, the people are confirmed by the article in their right to keep and bear their private arms.” – Tench Coxe, Philadelphia Federal Gazette, June 18, 1789