The lynching report is part of a longer project Mr. Stevenson began several years ago. One phase involved the erection of historical markers about the extensive slave markets in Montgomery. The city and state governments were not welcoming of the markers, despite the abundance of Civil War and civil rights movement memorials in Montgomery, but Mr. Stevenson is planning to do the same thing elsewhere.

Around the country, there are only a few markers noting the sites of lynchings. In several of those places, like Newnan, Ga., attempts to erect markers were met with local resistance. But in most places, no one has tried to put up a marker.

Image Bryan Stevenson, executive director of the Equal Justice Initiative, in front of the building, then a courthouse, where the lynching began. Credit... Brandon Thibodeaux for The New York Times

Efforts to count the number of lynchings in the country go back at least to 1882, when The Chicago Tribune began publishing each January a list of all executions and lynchings in the previous year. The Tuskegee Institute began releasing a list in 1912, and in 1919, the N.A.A.C.P. published what its researchers said was a comprehensive list of lynchings in the previous three decades. In 1995, the sociologists Stewart Tolnay and E. M. Beck researched the existing lists, eliminated errors and duplicates, and compiled what many consider the most accurate inventory to that time.

The report released Tuesday says that the new inventory has 700 names that are not on any of these previous lists, many of which Mr. Stevenson said were discovered during the compilation of the report.

Professor Beck, who teaches at the University of Georgia, has not reviewed the new list. But he pointed out that, with racial violence so extensive and carried out in so many different ways, compilers of lists may differ on what constitutes a lynching; the new list, as opposed to some previous ones, includes one-time massacres of large numbers of African-Americans, such as occurred in Arkansas in 1919 and in Louisiana in 1887.

“If you’re trying to make a point that the amount of racial violence is underestimated, well then, there’s no doubt about it,” Professor Beck said. “What people don’t realize here is just how many there were, and how close. Places they drive by every day.”