Nationwide, markers from Civil War heritage groups like the United Daughters outnumber comparable Union groups' markers by more than 2-to-1, NPR found. Confederate hospitals and Confederate cemeteries follow a similar pattern.
In all, markers about Confederates or the Confederacy are prolific, with more than 12,000 mentions. But the words "slave" and "slavery" show up only about half as many times.
When they do, many tell a racist myth about "faithful" slaves or otherwise diminish the reality of slavery. Others markers use racist language or support white supremacy.
As groups like the United Daughters disappeared from Tuskegee and other areas, historical markers gave those organizations and their message lasting and, in many cases, national visibility. The United Daughters put up markers as far away as Arizona, New Mexico and Washington, which weren't even states at the time of the war.
Officials with the United Daughters did not respond to NPR's requests for comment. But in a statement on its website, the organization says that its markers "simply represent a memorial to our forefathers who fought bravely" and that its members have "stayed quietly in the background, never engaging in public controversy."
That's not the history NPR found.
In November 1914, the United Daughters gathered for the group's annual convention at the swanky DeSoto hotel in Savannah, Ga., to hear the keynote speaker, the group's national historian, Mildred Lewis Rutherford.
"Slavery was no disgrace," Rutherford told the women, according to records from the convention. "The Negro race should give thanks daily. ... [Slaves] were the happiest set of people on the face of the globe. ...
"In all the history of the world, no peasantry was ever better cared for, more contented or happier," she said.
As she read these words, there hadn't been a slaveholder in the U.S. for half a century. But Rutherford's speech drove toward her final point: Slaveholders needed to be defended.
"These wrongs must be righted and the Southern slaveholder defended as soon as possible," she said.
Records in state archives show the group began requiring chapters to form "memorial marker committees" and focus their efforts on fundraising.
And they haven't stopped. While many groups have begun taking down Confederate symbols, the United Daughters of the Confederacy has helped put up 47 more markers over the last two decades.
"Markers are a reflection of the people who erect them"
So it was no surprise that when Bryan Stevenson arrived in Montgomery in the 1980s, long before he gained national acclaim for his work as executive director of the Equal Justice Initiative, and went looking for markers about slavery, he couldn't find one.