Thomas Henderson Loveless and James H. Loveless of PG County, MD
There seems to be some confusion between these two men. Some Loveless family history researchers (or publishers of Internet 'trees') have concluded that Thomas Henderson Loveless and James H. Loveless are the same person. This may be convenient but it is not true. The estate administration record for Thomas Henderson Loveless and the Guardianship papers for his minor children disprove that equivalence. Thomas Henderson Loveless married Mary Ann Jones 7 Feb 1815. The first wife of James H. Loveless is not currently known.
Thomas Henderson Loveless died in 1831. The following year James H. Loveless named a son Thomas H. Loveless (what the 'H' stands for is not explicitly known but it seems likely that it is Henderson) which suggests that Thomas Henderson Loveless and James H. Loveless may have been related, perhaps even brothers.
I am not aware of any historical document which explicitly states the middle name of James H. Loveless or his son, James H. Loveless, Jr. That it might be Henderson is yet to be proven, and seems unlikely to me.