Slavery was always legal and only after the civil war did restrictions come about (you can probably guess what group of people this was meant to target). Ignoring hyperbole, it is a fact that the "well regulated" portion of the 2A was understood to allow for restrictions until Scalia made up a reason to ignore it, again in 2008.
Im not going to defend the way NY is going about it, but to say there is no history for gun regulation by States is ignoring history and stare decisis.