Welcome to the Civil War in the Trans-Mississippi! This is a place where all who share an interest in the Civil War fought west of the Mississippi River can gather to ask questions, share information, and announce news.
There was a William Fletcher in the 45th Iowa Infantry, a 100 day regiment, raised in Keokuk. Ride Rover might actually be "Red Rover," a rebel side wheeler captured in 1962 and commissioned as a US hospital ship (see http://www.history.navy.mil/photos/sh-usn/usnsh-r/rd-rovr.htm). The Naval Historical Center seems to have a lot of info on the ship's personnel, nothing about a Fletcher. Sometimes these old guys promoted themselves after the war. Or maybe your reference is to a totally different William Fletcher.