A lady doing some research on him four years ago had him as captured May 25, 1862 at Winchester, Va and then back with his unit in July 62. Like you I had him on a disability discharge 11 May 1862. Then the picture I placed on the Arkansas Message Board that he drew and is noted Winchester, Va 1862, makes me think. This man worked for and was a parnter to Mathew B. Brady from 1849-1859 in N.Y., Philadelphia, and Conn. Washington State University has a number of his lithographies and art work in their collection. There is a beautiful rare map he drew of the environs of Kalisz, site of a battle fought between France (under Napoleon) and Russia. This was done before he moved to America in 1842. Most sources have his birth as 29 Oct 1813 at Versaelies, France. He photographed civil war troops and activites with partner Peale; Atwill, Joseph Fairfield according to Washington State University.