Gun laws in the US, state by state

President Obama has indicated a move towards strengthening federal gun control measures, but the reality is that the majority of gun legislation in the US is enacted at the state level. That has brought broad variations across the country, with states taking different approaches to issues ranging from sales, permits, licensing, self-defence and carry laws. This visualization by The Guardian describes the different kinds of gun regulations (or lack of them) state by state in the US.