Some say the Orlando shooting was not the deadliest mass shooting in history

Back in 1890, the U.S. Army's 7th Cavalry Regiment killed as many as 300 Native Americans -- men, women and children.

Ariela Gross, the John B. and Alice R. Sharp Professor of Law and History at USC Gould School of Law, points out other horrific incidents too: "Although precise numbers of deaths are impossible to specify, at least 100 African Americans were killed in East St. Louis, Illinois, in one bloody night in July 1917 (and) anywhere from 55 to 300 blacks were massacred in Tulsa, Oklahoma, in 16 hours in June 1921," she wrote for the Wall Street Journal.

But there are many other differences between the Wounded Knee Massacre and the massacres Gross referred to and the Orlando mass shooting that, in many eyes, put those events in different categories.

Incidents like the Virginia Tech massacre, the shooting at a movie theater in Aurora, Colorado, and the Newtown shooting fall under one modern definition of a mass shooting: one or few lone shooters, public space and multiple victims.

"The biggest difference between the hate crimes of the past and Sunday’s mass shooting is that they were group actions rather than the work of a single individual," Gross said. "That is an important difference, to be sure, but it shouldn’t obscure how much yesterday’s events did have in common with past massacres of hated groups."

The Tulsa race riots are another example of a mass killing that took place in the United States that does not fit the modern definition. While the Tulsa race riots were not an official entity like the 7th Cavalry Regiment, it was a group, which excludes it from the modern definition of a mass shooting.

However you define it, it might be most accurate to call the Pulse nightclub shooting the deadliest in modern U.S. history.

The most important point, though, is a tragedy is a tragedy. A life lost is a life lost.

>> The latest coverage of the Orlando nightclub shooting  

This video includes clips from WFTV, CNN, WKMG and images from the Library of Congress and Getty Images. Music provided courtesy of APM Music.