Many progressives seem to believe that the enormous growth of America’s prison population from the 1970s through the 2000s was driven primarily by the so-called War on Drugs. But is that assumption true?

Mostly false or misleading. Significant errors or omissions. Mostly make believe.

In fact, “mass incarceration” was driven primarily by the enormous rise in violent crime from the 1960s through the 1990s. Between 1961 and 1991, America’s violent-crime rate increased by 380 percent, with the murder rate increasing by 104 percent.

But aren’t U.S. prisons disproportionately filled with nonviolent drug offenders? Not even close. Before COVID, violent offenders represented 55 percent of all sentenced state prisoners, whereas drug offenders represented only 14 percent, according to the Bureau of Justice Statistics (BJS).

Those figures actually understate the share of violent criminals in state prisons, because many prisoners sentenced for a drug offense have also committed other crimes. As Fordham University law professor John Pfaff has written in the Washington Post, “If someone is arrested for a violent crime but ends up pleading guilty to a drug charge, his crime is classified as a nonviolent drug offense, even if the underlying incident—like a domestic violence case in which the victim won’t testify—is the reason the prosecutor sought prison time.”

It is true that, pre-COVID, drug offenders made up 46 percent of sentenced federal prisoners. But almost all of them (more than 99 percent) had been incarcerated for drug trafficking rather than possession, according to the BJS. Moreover, federal prisoners accounted for just 12 percent of all U.S. prisoners; state prisoners accounted for 88 percent.

Here’s another important point: Just as the prison population ballooned along with violent crime in the 1970s, 1980s, and early 1990s, it also began declining when violent crime went down. As of 2019, the overall U.S. imprisonment rate was at its lowest level since 1995, and the black imprisonment rate was at its lowest level since 1989.

At a moment when murders and shootings have spiked in many American cities, it is important to dispel popular misconceptions about the criminal-justice system—especially “mass incarceration.”

Read more: Stopping the Epidemic of Violence in American Cities.