Are you sure he wasn't in the military? I have:
Byrd, William Corporal 47th MO Infantry Co B Enlisted 4 Aug 1864 Mustered Out 29 Mar 1865 Age at Enlistment Age 19 NOT IN THE BATTLE OF PILOT KNOB (Co. B was at DeSoto). This muster info is probably on line at the Missouri Sec of State Web site.
He doesn't show up on the list of Qualified Iron Co Voters for 1865, but others from Union township do.