You are right...I did not state that correctly....Footnote found only 2 records for a "Griffin". Sorry.

His name was Owen David Griffin. He would have been 34 years old. He went by both O.D. and David Griffin.
I cannot find him on footnote or in the other online search. Another expert told me his record was probably lost/destroyed.

His Application of Indigent Soldier or Sailor signed July 10 1899 listed him as:

O.D. Griffin

He stated:
Served Co. F (5th or 6th) La Cavalry - served about 2 years only 8 months in the field. Sore eyes prevented service most of the time.

His application was approved August 19 1899

His widow applied for his pension (file #1917) was approved 22 September 1905

Thank you so much for all your help.