As far as the park not knowing I cannot say, other than if when talking with the person they thought you were looking for an actual Texas regiment rather than a Tennessee unit with some Texas guys. This happened a lot with units at Donelson, the 50th Tennessee infantry had an Alabama company within its regiment. The park historian ther is Jimmy Jobe.

As far as finding out, you would need to find or compile a list of the men who were in the unit prior to Donelson, then compile a list of the guys who were reconsolidated in the 23rd Texas, compare the list, find the guys who are missing, go to footnote.com and start reading the cards to find out what happened to those missing men. That would be a start.

John Walsh