This paper studies the transmission of a county’s historical exposure to the U.S.frontier into its consumers’ present-day preferences for firearm ownership and regulation. Counties with an additional decade on the frontier between 1790–1890 have 1.2 percent higher rates of firearm ownership between 1999–2019 than their less-exposed counterparts, equivalent to 10 percent of the gap in contemporary rates of firearm ownership between Illinois and Texas. Consumers who live in counties with greater frontier exposure disproportionately purchase more firearms following nationwide demand shocks and increased support for a federal assault rifle ban following the 2017 Las Vegas Mass Shooting Event. The contemporary debate around firearm regulation should account for heterogeneity in its historical antecedents across the U.S.