Reply #38: Quoted below from page 7 of Heller:

[jody]

b. “Keep and bear Arms.” We move now from the
holder of the right—“the people”—to the substance of the
right: “to keep and bear Arms.”

Before addressing the verbs “keep” and “bear,” we interpret
their object: “Arms.” The 18th-century meaning is no
different from the meaning today. The 1773 edition of
Samuel Johnson’s dictionary defined “arms” as “weapons
of offence, or armour of defence.” 1 Dictionary of the
English Language 107 (4th ed.) (hereinafter Johnson).
Timothy Cunningham’s important 1771 legal dictionary
defined “arms” as “any thing that a man wears for his
defence, or takes into his hands, or useth in wrath to cast
at or strike another.” 1 A New and Complete Law Dictionary
(1771); see also N. Webster, American Dictionary
of the English Language (1828) (reprinted 1989) (hereinafter
Webster) (similar).

The term was applied, then as now, to weapons that
were not specifically designed for military use and were
not employed in a military capacity. For instance, Cunningham’s
legal dictionary gave as an example of usage:
“Servants and labourers shall use bows and arrows on
Sundays, &c. and not bear other arms.” See also, e.g., An
Act for the trial of Negroes, 1797 Del. Laws ch. XLIII, §6,
p. 104, in 1 First Laws of the State of Delaware 102, 104
(J. Cushing ed. 1981 (pt. 1)); see generally State v. Duke,
42 Tex. 455, 458 (1874) (citing decisions of state courts
construing “arms”). Although one founding-era thesaurus
limited “arms” (as opposed to “weapons”) to “instruments
of offence generally made use of in war,” even that source
stated that all firearms constituted “arms.” 1 J. Trusler,
The Distinction Between Words Esteemed Synonymous in
the English Language 37 (1794) (emphasis added).

Some have made the argument, bordering on the frivolous,
that only those arms in existence in the 18th century
are protected by the Second Amendment. We do not interpret
constitutional rights that way. Just as the First
Amendment protects modern forms of communications,
e.g., Reno v. American Civil Liberties Union, 521 U. S. 844,
849 (1997), and the Fourth Amendment applies to modern
forms of search, e.g., Kyllo v. United States, 533 U. S. 27,
35–36 (2001), the Second Amendment extends, prima
facie, to all instruments that constitute bearable arms,
even those that were not in existence at the time of the
founding.