I found this in Mo State Archives
William Byrd - No middle initial
Jeffrey's 8th Mo Cav in Marmadukes old Brigade
Enrolled June 1863
Served until Oct 1864
Participated in fight at Little rock and a great many skirmishes, also in engagements of Pine Bluffs and Ironton, at latter place he was detailed to take care of the wounded confederates and upon arrival of the federals after the battle, he was taken prisoner and paroled
history of southeast Mo 1888
page 747 Cape Girardeau co.
How do these dates stack up?