My great-grandfather, Major Ramon de Aragon, was a medical officer in the 9th Texas Infantry from the reorganisation at Tupelo in 1862 till the end. From early 1864 on he was the senior surgeon of Ector's brigade and probably is the one who did the amputation of General Ector's leg when he was wounded in Atlanta.
I wrote a book about the major several years ago, primarily for the family, but have published it on Amazon.com -- "De Aragon, the Chronicle of a Confederate Surgeon". Here's the link:
I also recommend the published diary of J. K. Street, which also can be found on Amazon. He was a private in the 9th Texas. The diary is very extensive.