The United States is not the most violent society. Drug oligarchies and broken tribal nations are much more lethal places to live. But among the 23 wealthiest countries, the United States is easily the bloodiest: homicide gun rates are 19.5 times higher here than in other high-income countries.
The Harvard Injury Control Research Center assessed the literature on guns and homicide and found that there’s substantial evidence indicating that more guns mean more murders. This holds true whether you’re looking at different countries or different states.