The Articles of Confederation.
The AofC did not really create a nation as we think of one. What they really did was created something more akin to the European Union; but, weaker. One of the things in the AofC was a statement about militias. "No vessel of war shall be kept up in time of peace by any State, except such number only, as shall be deemed necessary by the united States in congress assembled, for the defense of such State, or its trade; nor shall any body of forces be kept up by any State in time of peace, except such number only, as in the judgement of the united States, in congress assembled, shall be deemed requisite to garrison the forts necessary for the defense of such State; but every State shall always keep up a well-regulated and disciplined militia, sufficiently armed and accoutered, and shall provide and constantly have ready for use, in public stores, a due number of field pieces and tents, and a proper quantity of arms, ammunition and camp equipage."
In many ways the Articles of Confederation were a wealthy man's privilege in legal form. It was 13 oligarchies controlling their own individual states, true states rights. The current Constitution was fully ratified in May of 1790 (though 11 states had already ratified and were technically the United States). The US Constitution was meant to limit state rights and strengthen the federal government because the Articles of Confederation had failed so badly.
Lets get back to gun rights for a moment. When preparing the "Bill of Rights", James Madison originally wanted it to say, "The right of the people to keep and bear arms shall not be infringed; a well armed, and well regulated militia being the best security of a free country: but no person religiously scrupulous of bearing arms, shall be compelled to render military service in person." Notice how the same sentence is about keeping and bearing arms and the ability to refuse military service in person. That in person part meant that you could pay someone else to do your fighting for you and that happened a lot. The Bill of Rights went into effect on December 15, 1791. You know how we know that the Constitution did not give you an individual right to bear arms? Simple, it was ILLEGAL for slaves to own guns in many states. They were counted as 3/5ths of a person according to the Constitution, yet, they could not own guns. I should also point out that Japanese Americans who were put in determent camps during World War II. Heck, in the 1800s the police often required you to turn in your guns before coming into town and that was cowboys. Even today we prohibit felons from owning guns and from voting. Don't tell me you a constitutional strict constructionist if you think felons lose the ten amendments, that my friends is not in the constitution.
A true strict constructionist attempts to determine what the people who approved the Constitution and amendments meant when they wrote it and lets be clear, they didn't believe the same things we do. The Constitution was meant to keep state oligarchies in power while giving greater central control over the nation to the central government. If you want to be really strict in your construction of the Constitution, the abolition of slavery is sort of a dodgy question as there was no Constitutional Amendment abolishing it, that was done by executive decree, specifically, The Emancipation Proclamation and really only applied to Confederate states.