I don't think it was deleted because of the 2nd Amendment issue itself. If the 2nd Amendment was relevant to the organization of the artillery in the ACW and the latter was the source of the question, then it would be on topic.

It was most likely deleted because you said you were asking about the Revolutionary War in your follow up. That would make it off topic for this particular forum. If you were asking about Revolutionary War and pre-ACW militia to better understand ACW artillery organizations, then it would be on topic.

The artillery forum is not a logical choice for a philosophical discussion about exactly what "is part or our natural born rights."