Any man or women in free America until 1968 could own a firearm. It worked pretty well until then.
However with movement groups arming themselves in the civil rights era, they wanted to legaly be able to keep people previously arrested for demonstrating or radical activists from being able to assemble once again legaly armed.
A whole number of laws were aimed at stopping this. From laws against being armed in or around a state or federal building many places, to laws against felons having firearms. To laws against anyone being armed while demonstrating or striking.
The effect on crime has been nill, it however is a useful tool in implementing a more authoritarian state as anyone at will can be branded unfit to legaly possess effective deterent.
However it also has an effect against our culture. In many places felons can still vote, some while in jail or prison, others after they are out, and others have to do some steps to have that restored. Once someone is permanently barred from possessing arms you can be very sure they are going to vote in favor of bills that reduce the number of arms others have, or restrict thier possession or transport.
It is hard to find exact numbers on the percentage of felons in the nation. At any given time there is over 7 million people incarcerated, or on parole/probation, 1 in 31 adults. But that is only the people who recently did something. If we use statistics and assume that based on them most of the offending population is 18-25, then adjust for total number of Americans in that age bracket. Lets see census says
http://factfinder.census.gov/servlet/SAFFFacts on front page that there is 182,211,639 over 25, and 209,128,094 over 18. That gives us 26,916,455 people in America 18-25. If even just half of the 7 million people incarcerated or on parole/probation are of that age group 4.5 million, then that means about 1 in 6 Americans in the age bracket most adults earn criminal charges in, then close to 1 in 6 from 18-25 in modern society become prohibited.
If we use closer to the whole 7 million, say 6 million, then its about 1 in 4.5 adults 18-25.
That means as that age bracket goes to 26-32, and a new 6 million adjusted upwards for population gain are branded every 7 years then we will have a lot of people unfit to own a firearm. Yet most of these people will still be able to vote.
By the time current 18-25 individuals reach 50-60 years of age close to 20% of American adults will have been on parole, probation or incarcerated based on current statistics.
If a good portion of them are felons, we just gained a very large segment of the population who will not vote for others to be allowed to have something they cannot. Much larger than the number of people that belong to the NRA.
Also if we look at the purpose of the 2nd amendment, to deter tyranny, government being able to brand trouble makers unfit to be armed basicly undoes the purpose. Every founding father we had was a felon under British law.
I first took note of just how many American's are felons at least in my district when I was reporting for jury duty. They called various groups up who had circled one of the numbers that made them ineligable to serve. When they called the number that was "have you ever been convicted of a felony" to turn thiers in seperate, about 20% of the room got up and turned it in and left. I looked around the room, noticing even the nice old lady who I had just had a short polite discussion with was among them.
I believe it is circumstantial ..
No what was circumstantial was the number of people that would have been allowed to live. Consider that horse theft was punishable by death. Horses were people's transportation back then, so that would be the modern equal of grand theft auto. Yet nobody is executed for grand theft auto in modern times.
Going into debt and being unable to pay your debt was liable to end you up in debtor's prison. Well based on the current housing market slump and people being unable to pay thier mortgages and homes defaulting all over the nation, a lot of Americans would be eligable for prison.
Yet most sentences were relatively short back in the day. Someone was either killed if it was serious enough, or they spent at most a few years and then were put back into society a free man. Many crimes that are felonies or serious misdemeanors today were punished by a night in the local jail back then, or some time in the pillory or stocks in public being humiliated.
Yet once released they were free to rejoin society as a free man, having paid thier dues.