In addition to what Bartholomew and Frank wrote, there's the pleasing Footnote 9 of the Heller decision:
At the time of the founding, as now, to “bear” meant to
“carry.” See Johnson 161; Webster; T. Sheridan, A Complete
Dictionary of the English Language (1796); 2 Oxford
English Dictionary 20 (2d ed. 1989) (hereinafter Oxford).
When used with “arms,” however, the term has a meaning
that refers to carrying for a particular purpose—
confrontation. In Muscarello v. United States, 524 U. S.
125 (1998), in the course of analyzing the meaning of
“carries a firearm” in a federal criminal statute, JUSTICE
GINSBURG wrote that “urely a most familiar meaning is,
as the Constitution’s Second Amendment . . . indicate:
‘wear, bear, or carry . . . upon the person or in the clothing
or in a pocket, for the purpose . . . of being armed and
ready for offensive or defensive action in a case of conflict
with another person.’ ” Id., at 143 (dissenting opinion)
(quoting Black’s Law Dictionary 214 (6th ed. 1998)). We
think that JUSTICE GINSBURG accurately captured the
natural meaning of “bear arms.” Although the phrase
implies that the carrying of the weapon is for the purpose
of “offensive or defensive action,” it in no way connotes
participation in a structured military organization.
From our review of founding-era sources, we conclude
that this natural meaning was also the meaning that
“bear arms” had in the 18th century. In numerous instances,
“bear arms” was unambiguously used to refer to
the carrying of weapons outside of an organized militia.
The most prominent examples are those most relevant to
the Second Amendment: Nine state constitutional provisions
written in the 18th century or the first two decades
of the 19th, which enshrined a right of citizens to “bear
arms in defense of themselves and the state” or “bear arms
in defense of himself and the state.” 8 It is clear from those
formulations that “bear arms” did not refer only to carry-
ing a weapon in an organized military unit. Justice James
Wilson interpreted the Pennsylvania Constitution’s arms bearing
right, for example, as a recognition of the natural
right of defense “of one’s person or house”—what he called
the law of “self preservation.” 2 Collected Works of James
Wilson 1142, and n. x (K. Hall & M. Hall eds. 2007) (citing
Pa. Const., Art. IX, §21 (1790)); see also T. Walker, Introduction
to American Law 198 (1837) (“Thus the right of
self-defence [is] guaranteed by the [Ohio] constitution”);
see also id., at 157 (equating Second Amendment with
that provision of the Ohio Constitution). That was also
the interpretation of those state constitutional provisions
adopted by pre-Civil War state courts.9 These provisions
demonstrate—again, in the most analogous linguistic
context—that “bear arms” was not limited to the carrying
of arms in a militia.