I may regret wading in to this, but I’m going to push back a bit on that premise.

There’s a lot of American history, and a lot of tragedies. Some, like the Hindenburg explosion (36 dead) are well known; some, like the Eastland capsizing (844 dead) are not. Why do we know the Triangle Shirtwaist Fire but not the New London school explosion? The Great Chicago Fire but not the much deadlier inferno that destroyed Peshtigo, Wis., the very same night? Perhaps historiography offers a grand unified theory, but it seems to just be a maddening combination of publicity, psychology, and usefulness in explaining or remembering what came later.

Something not being well known nationally is not the same as it being suppressed. The Tulsa massacre was certainly well known locally, but Tulsa—like most cities—preferred to emphasize its positive and business-friendly aspects rather than its past sins. So it put its 1957 claim as “America’s Most Beautiful City” on its welcome signs while relegating the 1921 riot to a historic marker. High school and undergraduate survey courses on American history always have to pick and choose what few specific events to teach in trying to give an understanding of later developments and our current situation.

In the last two decades, several things have brought the Tulsa massacre to a new prominence, one that may even be outsized compared to similar events in Ocoee, Fla., or Springfield, Ill., to name just two. One is that oral traditions of mass graves and huge numbers of deaths in Tulsa, never substantiated, have survived to become part of the folk history. For better or worse, this has occurred in our current post-truth world where absence of evidence cannot be assumed to be evidence of absence, but only of some deeper conspiracy.

Second is that somewhere, somehow, the title of “Black Wall Street” has now been attached to Greenwood, even though I know of no national financial institutions that were ever located there, and no way that it was substantively different from the African-American business districts of Memphis, Kansas City, or Dallas. I mean in no way to diminish the investments or tragedies of those who lost everything in the destruction of Greenwood, but the appellation “Black Wall Street” erroneously suggests the loss of a financial capital with nationwide importance.

Third, the shoutout it was given as a scene-setter for the Watchmen series gave the Tulsa massacre a new focus in popular culture. Seeing the firebombings and murders on film, as the backstory of the series’ heros, gave the events an immediacy and an emotional punch they would not have—did not have—as written recountings in the various sober historic reports.

And finally, the centenary comes at a time when we are as a nation rethinking our relationship with race, and reexamining our history with it. This weekend’s commemorations of the events in Tulsa include a presidential visit, television specials on four different networks, and an elaborate virtual reconstruction by the New York Times of the lost neighborhood. It’s hard not to think they would have been a bit more local had they occurred two years ago—as the 2019 remembrances of Chicago’s (equally deadly) 1919 race riot indeed were.

I would conclude not by blaming the teachers and authors of our past for the emphasis they chose, but by encouraging everyone to look at your own city’s or county’s local history to see what overlooked events might tell a fuller and more nuanced tale of race relations in America.

In terms of contemporary progroms and other forms of collective anti-black violence, please see this answer of mine.