Here's the citation:

Richard H. Adams, Jr. papers. (MS#0358)
Biographical note: Richard H. Adams, Jr. b. 1841 at "Altwood", Marengo County, Alabama; served as officer during Civil War with 5th Alabama Infantry Regiment and in Engineer Corps on General Wheeler's staff, captured near Nashville; prisoner of war Sept. 1863-June 1865, one of "immortal 600"; engineer after war; d. 1896 at Radford, Virginia. Descriptive note: Civil War papers (ca. 80 items) of Captain Richard H. Adams, Jr. Consist of manuscript diary kept while serving with the 5th Alabama Regiment in Virginia, April-June 1862, with accompanying typewritten transcription. Transcriptions only of two additional diary volumes (Sept. 1862-March 1863; and prison diary, 1864-1865); 47 original letters (Nov. 1863-Sept. 1866) to Lottie Putnam Adams, most written before their marriage while he was a prisoner of war; 23 original letters from Lottie to Richard, March 1864-Jan. 1865; typescript "Account of Wheeler's Raids" written after the war; "friendship book", March 1865, containing inscriptions by fellow prisoners; 2 photographs of Adams; miscellaneous documents and clippings. Letters reflect ongoing courtship and generally concern personal and family matters; some references to war and prison life. Diaries contain information about camp life, battles, prison life.

Records of the 5th Cavalry are as rare as hen's teeth