Sears appears in this regiment, not Burnett's 13th Texas Cavalry.
The NPS departed from its usual convention and labeled this regiment as "Volunteers" rather than infantry. That may be because the regiment included companies organized for cavalry or artillery service. This was a common practice among Texas regiments organized for coastal service. For instance, Hobby's 8th Texas Regiment included infantry, cavalry and artillery companies.
The NPS lists 3,500 names on the rolls of this regiment.