Claims about the past, and the range of voices making those claims, are continually changing in any society, perhaps especially in democracies. The past few decades—the period when public history emerged as a professional field—have been a time of particularly vigorous public debate about the meanings of the past in many places. Although some people worry that this is a sign of social cohesion breaking down, historians tend to take a more hopeful view of these more inclusive—if more contentious—public debates about history.

Where it gets tricky is in balancing those various voices, including those of historians themselves. If there’s no one single authoritative, stable account of the past, isn’t everyone’s version just as good as everyone else’s?

This is where historians make a case for the value of their own practices of assessing evidence and conducting peer review as an important part of any public discussion about the past. Done well, historical interpretation can complement—and sometimes challenge—histories rooted more in personal and community memory or in efforts at present-day action.

That doesn’t mean professional historians have the final word. But they can help create some checks and balances within public dialogue about the past. Historians’ carefully-considered knowledge almost always makes the past seem less straightforward, challenging too-simple stories. It can also serve as a platform for contesting clearly false claims—for example, the idea that the Holocaust never happened. It can help in taking a wider view of the many competing, sometimes contradictory versions of history that are always circulating in the public realm.

For example, for many years slavery was not a topic broached by US National Park Service officials at Civil War battlefield parks. In the early twenty-first century, the NPS made a careful re-evaluation of that approach, based in part on current historical scholarship about how mid-nineteenth-century Americans themselves had understood the causes and stakes of the war. As reflected in the 2001 collection Rally on the High Ground, the NPS concluded that race and slavery were inescapably part of the history of battlefield parks. Many Americans continue to disagree with this stance, but the NPS stands by its assessment that the historical evidence supports its shift in interpretation.