The Second Amendment was adopted December 15, 1791. It was adopted as a result of Americans having to live under the control of the tyrannical British Government and its troops. There were no limits as to what kind of gun or firearm a person could own or possess. These muskets and rifles were the state of the art weaponry at the time. The Second Amendment is a guarantee that American Citizens can defend all the God given Freedoms every human being should have as part of life on this planet.
We do not let homicidal maniacs roam our streets, planting bombs, wielding knives, mowing down innocent women and children on our streets, or going in our schools with any type of weapon to harm people. But, the device or tool used to accomplish this horror is not the problem. We as a society have to commit to expend the time and devotion necessary to identify and neutralize these monsters regardless of what weapon or tool they choose to carry out their crimes.
Every (sane) US Citizen of legal age has the right to possess and carry a firearm. Period.