From Library of Congress---The Robin G. Stanford Collection LC-DIG-stereo-1s04500 American Zouave Soldier's Civil War 1860's More on history of Zouaves at Aramco-World https://www.aramcoworld.com/Articles/March-2017/America-s-Zouaves
Collector Robin Stanford sold more than 500 images to the Library of Congress for an undisclosed amount, the Washington Post reports. "They’re just tremendously significant," said Bob Zeller, president of the Center for Civil War Photography. "These are not post-war. These are actual scenes of slavery in America."
Stanford, 87 and of Houston, had been collecting the images—many of them are stereo pictures, or two of the same frame that are printed on one card and meant to be seen in 3-D via a stereo viewer—since the 1970s.
Learn more at Time article Go Inside a Newly Public Trove of Rare Civil War-Era Pictures