in 1816 arguments to a jury. The first is by defense lawyer Joseph Reed Ingersoll, who would eventually become a prominent Congressman:

I think it is apparent ... [t]hat after the attack, and threats, and the avowal of an intention of the part of captain Carson to take away his life, he had a right to bear arms on the plainest principles of self-defence....

Having the right of access to the house, he was justifiable in protecting himself by the only means which reduce the powerful to a level with the weak. The constitutions, both of the Federal government and of the commonwealth of Pennsylvania, secure to every citizen, the right to bear arms, and the only question that remains, is whether the exercise of the right be compatible with disretion.

The second is by another defense lawyer, William Rawle, a prominent early American lawyer who would nine years later write a treatise that likewise supported the individual rights view of the right to bear arms and of the Second Amendment:

There is only one circumstance remaining worthy of notice; that of arming himself. The constitution of this state has expressly secured the right to carry arms. In Art. IX, Sect. XXI, "the right of the citizens to bear arms, in defence of themselves and the state, shall not be questioned."

The right, in defence of the state is, where foreign invasion occasions it to be in danger; that of defence of themselves continues through their lives, and, therefore, there is not any thing in opposition to Richard Smith's bearing arms, not against the officers of the law, but against the lawless attack of an individual he had to fear. If, in a conversation with another, attacked by him, he had caught up and fired that pistol, in fear of his person suffering great bodily harm, the law would have considered it as excusable homicide. Does his carrying that pistol, after Carson's previous attempt on him, for self defence, make him culpable? No -- the constitution allows it, especially when the assistance of the magistrates could not be obtained; it follows, that the use of this pistol was not unlawful when accompanied with these circumstances. Suppose he had been taken up for carrying a pistol in his bosom, and upon complaint being made to some of the learned magistrates, he had defended himself, by saying, he carried it in fear of his life; or were to say even, I do not carry it -- it is in my chamber -- the judge would answer, pursue, uniformly, the same conduct; you are perfectly justifiable, and have a right to be armed in your own defence.

Trials of Richard Smith Together with the Arguments of Counsel, the Charges and Sentence of the President 157, 205 (1816).

These are small pieces of evidence, but I ran across them and thought I'd note them, especially since they are from only 25 years after the Bill of Rights was ratified, and since the second is one of the few sources that discusses the "in defence of themselves and the state" locution that's common in state constitutions. And the quotes help support, I think, the view that the Second Amendment was widely understood as securing an individual right to bear arms, including in self-defense, to the point that lawyers could confidently and casually assert this even in cases where they didn't have that much to gain from it: If Ingersoll wasn't sure that his audience would agree that the Second Amendment secured such a right, he could easily have just relied on the state constitutional right, which was the one most directly relevant in this state prosecution.

An interesting tidbit: The prosecutors were Jared Ingersoll -- defense lawyer Joseph Ingersoll's father -- and one Edward Ingersoll, who I take it was also related, though I'm not sure exactly how.