When the Second Amendment to the U.S. Constitution was ratified, on December 15, 1791, assault weapons, assault-like weapons, automatic weapons, and semi-automatic weapons did not exist. Therefore, it is not unconstitutional to ban these weapons.
Muskets, bayonets, and cannons were the weapons of the day. When James Madison wrote the Second Amendment, at the behest of a few of the states, he and our country’s leaders wanted us to be able to protect ourselves. Because today’s weapons were not even conceived of then, Madison wrote a law about the weapons that were being used at the time. Those weapons included cannons. However, while armies of countries possessed cannons, our founders did not expect the average colonist to own one. It probably never even entered their extremely intelligent heads that an individual would own a powerhouse military armament. The cost alone would have been prohibitive.
Over the centuries, personal weapons became more powerful, accurate, and affordable. Now, our leaders must address the weapons available today. Assault weapons and their like must be banned for personal ownership; we cannot tolerate any more mass murders committed by people with these guns.
Our founders approved the ownership of muskets and bayonets. Our leaders must determine what can be owned in our own time, just like Madison did more than 200 years ago, when he wrote our hotly contested Amendment.