I received this link and description in an e-mail.

http://www.railsplitter.com/sale12/images/3383.jpg

Here's the description:

A superb and quite rare mounted albumen, 8 x 6", of members the Louisiana Native Guard learning to read at Port Hudson, Louisiana in 1863 at a school set up for the benefit of the soldiers and other freedmen. One of the first all-black units in the Civil War, the Louisiana Native Guard was formed after the fall of New Orleans by Benjamin Butler on September 27, 1862. Composed primarily of free blacks from New Orleans, the ranks soon began to swell with escaped slaves from the surrounding countryside necessitating additional regiments, all of which were commanded by Col. Nathan W. Daniels, whose diary of his service was published in 1998. The regiment, whose historical significance is as great as the fabled 54th Massachusetts, consisted of all-white field grade officers, all-black line officers as well as enlistees. When Nathaniel Banks replaced Butler as Commander of the Department of the Gulf, he attempted to systematically purge all black line officers with only limited results. On May 27, 1863, the regiment participated in the first assault at the Siege of Port Hudson. Soon afterwards, the regimen was dissolved and folded into the Corps d'Afrique. That too was later dissolved, becoming part of the 73rd and 74th United States Colored Troops in 1864. This rare, arresting image shows a large group of enlisted men (including several corporals) holding books (some sharing) obviously posed for the camera. At center, a white officer stares at the camera while holding a book open for the benefit of two black enlisted men looking over his shoulder. A testament to the pervasive racism in the Union army, almost all of the white officers stand (save for a young boy, possibly a servant) at the far left while the blacks soldiers stand toward the right. Also note the high-ranking field officer with the double-breasted coat and saber in hand. A truly brilliant image capturing a critical period in the lives of many of those shown: recently freed slaves now being empowered not only with guns, but with words. Photographer unknown, one extant copy of this image is known to be housed in the Chicago History Museum, but we have yet to encounter any other exmaples. Small cut to emulsion at right, a few toned spots, else a fine crisp image. (Est. $4,000-5,000)