It's interesting to note that most americans and therefore everyone else don't really understand what the second amendment actually means.
Much conjecture exists about the interpretation of the amendment.
The second amendment simply (or not so) reads:
"A well regulated Militia, being necessary to the security of a free State, the right of the people to keep and bear Arms, shall not be infringed."
The interpretation of this is what so many americans, in particular the NRA, seem to argue about. There is MUCH that can be read about this.
However:
"The Supreme Court makes the ultimate determination of the Constitution's meaning, and it has defined the amendment as simply granting to the states the right to maintain a militia separate from federally controlled militias."
And this seemed to work ok up until the mid 70s...
Enter now the NRA, who actually before this time were fairly sensible and mostly concerned themselves with gun safety. The new leader of the NRA had new ideas. He challenged the definition and interpretation of the second amendment to include the rights of the individual. At the time they were largely ignored.
But then along came the 80s...
Besides the insufferable elctro pop, Reagan, a known gun rights activist, is now in power. Add to that Orrin Hatch and his supposedly long lost proof that the second amendment did in fact allow for the right of private citizens to carry weapons and you've got an NRA badge wearers wet dream.
They kept at the government. They even funded academic studies to help prove their point.
So by the late naughties, everyone had started to believe them. The supreme court was in favour of individual rights. Justice Antonin Scalia ruled that
“handguns are the most popular weapon chosen by Americans for self-defense in the home, and a complete prohibition of their use is invalid.”
Luckily, Scalia could not justify ownership of any other form of weapons (assault rifles etc).
So, for now, we seem to be stuck with the current version of events that says americans can carry handguns. Lucky us </end sarcasm>.