The result of George Stoneman's contribution to the 1863 Chancellorsville Campaign was not as devastating as planned, but his March-April 1865 cavalry raid, criss-crossing through parts of Tennessee, Virginia, and North Carolina, cut a swath of destruction through a Confederacy already on its knees. In terms of published histories, the 1865 raid usually merits just a chapter or two in more general works, along with the occasional magazine or journal article. Back in 1973, Thomas Ramsey self-published a book length account (now scarce) titled The Raid: East Tennessee, Western N. Carolina, Southwest Virginia, the value of which is unknown to me. However, it appears the relative obscurity of the operation's details will change in September with the planned release of Chris J. Hartley's Stoneman's Raid, 1865 (John F. Blair, 2010). The study will be quite substantial in length and promises the most comprehensive treatment to date.
[For those unfamiliar with the publisher, here is a link to John F. Blair's Civil War catalog.]