Well, if they go far back enough, they'll find laws that stated slavery was legal and kings can sentence you to death on a whim.Another gem from the State of New York trying to defend their law - they cite a law from the 1200's as basis for history of limiting carrying of arms:
"It provided that, with some exceptions, Englishmen could not “come before the King’s Justices, or other of the King’s Min- isters doing their office, with force and arms, nor bring no force in affray of the peace, nor to go nor ride armed by night nor by day, in Fairs, Markets, nor in the presence of the Justices or other Ministers, nor in no part elsewhere, upon pain to forfeit their Armour to the King, and their Bodies to Prison at the King’s pleasure.” 2 Edw. 3 c. 3 (1328).
Respondents argue that the prohibition on “rid[ing]” or “go[ing] . . . armed” was a sweeping restriction on public carry of self-defense weapons that would ultimately be adopted in Colonial America and justify onerous public- carry regulations. Notwithstanding the ink the parties spill over this provision, the Statute of Northampton—at least as it was understood during the Middle Ages—has little bearing on the Second Amendment adopted in 1791. The Statute of Northampton was enacted nearly 20 years before the Black Death, more than 200 years before the birth of Shakespeare, more than 350 years before the Salem Witch Trials, more than 450 years before the ratification of the Constitution, and nearly 550 years before the adoption of the Fourteenth Amendment."