It’s already been said again and again in the span of a day: The shooting at the Route 91 Harvest Festival in Las Vegas, with at least 58 dead and hundreds injured, was the deadliest mass shooting in American history.

But was it really? The answer, it turns out, is surprisingly complicated.

The short version: It was definitely the deadliest mass shooting in recent history. But if you look further back in the US’s past, the real answer depends on how you define a mass shooting.

The National Association of Black Journalists and the National Association of Hispanic Journalists, for example, pointed to two past attacks as examples of previous massacres with higher death tolls than the Las Vegas shooting.

In 1873, an all-black militia defended a local courthouse in Colfax, Louisiana — fearing, at the height of racial tensions after the Civil War, that white supremacists were about to topple the regional government, which was evenly split between white and black citizens at the time. Soon after, a mob of more than 150 white men — made up of Southern Democrats, former Confederate soldiers, members of the Ku Klux Klan, and the paramilitary White League — surrounded the courthouse and attacked. Three white men and as many as 150 black men died, according to Smithsonian.com.

Another example: The 1917 East St. Louis Massacre — a white-led race riot — left at least 39 black people and nine white people dead, according to official estimates. But as Smithsonian.com noted, it’s widely believed that more than 100 black people were killed during the three-day massacre.

There are many such events throughout American history, from the destruction of “Black Wall Street” in Tulsa, Oklahoma, to the 1919 mass lynching in Arkansas. After the Civil War and during the ensuing 100-year struggle for basic civil rights protections, white groups often lashed out in violence to try to assert their control of the South — and a lot of people, particularly black Americans, died.

Before that, there were also horrific attacks on Native American populations, such as the Sand Creek Massacre. (Although many of these events can be seen as acts of war.)

Were any of these events mass shootings? That depends on which definition you use.

The surprisingly contentious definition of a mass shooting

Mass shootings are, broadly speaking, typically seen as events in which a shooter or multiple shooters open fire on another group of people in public. Whether it rises to the level of a mass shooting typically depends on the death or injury toll — some organizations use a definition that includes any shooting in which at least four people were shot, others use definitions in which at least three or four people were shot and killed, and some use even narrower definitions that try to control for the details of the shooting.

For example, the Gun Violence Archive and Vox count any event in which four or more people were shot, but not necessarily killed, at the same general time and location. Some criminologists, such as Northeastern University professor James Alan Fox, prefer to include any shooting in which four more people are killed. Mother Jones editor Mark Follman, who has done a lot of reporting on mass shootings, prefers a very narrow definition that includes shootings in which four or more people are killed and excludes all domestic, gang, and drug violence. And there are even more ways to interpret the definition of a mass shooting.

There is some debate about which definition is correct. Follman argues that his version defines mass shootings in the same way many Americans think of them, and that it’s preferable for researchers to use a narrow definition to better gauge the common causes of mass shootings. But this seems to gloss over other horrific incidents in which a lot of people are shot, including in the privacy of their own homes but also in public. (As one example, there’s a bizarre debate about whether gang-related school shootings are “real” school shootings.)

Depending on which definition you use, it’s unclear if the examples given by the National Association of Black Journalists and the National Association of Hispanic Journalists count as mass shootings.

The Colfax Massacre, as deadly as it was, doesn’t align with what many Americans consider a typical mass shooting. It wasn’t that a person or small group of people shot and killed many other people. It was more of a traditional battle — in which two large armed groups clashed, killing a lot of people (almost entirely on the black side, which was simply outgunned). This is not what Americans typically have in mind when they think of a mass shooting.

The 1917 East St. Louis Massacre, meanwhile, wasn’t just one event. The final death toll was the result of a series of events over three days as a white-led mob rioted and brutally attacked and killed their black neighbors as a result of a labor dispute. Again, not what most people think of when they think of a mass shooting.

And the East St. Louis Massacre also didn’t involve just guns; people used a variety of weapons, which was fairly standard practice in lynchings and race riots. That obviously muddies whether and to what extent it can be considered a mass shooting.

Another complicating factor is these types of attacks were typically endorsed by the government or, at the very least, by much of the local community. One of the defining characteristics of mass shootings today is that almost everyone in America views them with total shock and horror.

There’s fear about overlooking America’s history of anti-black violence

For organizations like the National Association of Black Journalists and the National Association of Hispanic Journalists, the concern is that events in which predominantly black people and other minorities were killed may go ignored if the media glosses over the US’s history of racist violence and focuses only on modern travesties. As the groups said in their statement, referring to the Las Vegas shooting as the worst in US history “negates several other incidents in U.S. history, many involving minority victims.”

There is no question America has a horrific history of anti-black violence. A report by the Equal Justice Initiative found lynchings of African Americans by white communities in the South killed more than 4,000 people between 1877 and 1950. If anything, that’s an underestimate; the report only covered 12 Southern states, and many of these horrific attacks went unreported or underreported, making it hard to pin down just how many people were killed. But it’s still an enormous death count.

Complicating the basic understanding of what is a mass shooting today, however, is that this particular type of anti-black violence is generally a thing of the past. And when we talk about mass shootings in modern terms, Americans and the media are mostly thinking of the kinds of violence we are acclimated to and most concerned about, particularly shootings in public spaces in which a lot of people are suddenly killed and injured.

But this is all largely semantics. The point is there have been deadlier violent acts in America’s past, regardless of how you define them, than what happened in Las Vegas over the weekend. And the Las Vegas mass shooting was the deadliest in, at the very least, modern history — so it was an unusually horrible event, regardless of whether someone’s definition of mass shooting makes it the deadliest of all time. More than anything, perhaps that’s what Americans should take away from this walk through US history.