William's parents are said to be John CUPP & Sarah WILHELM, but John was born, lived, and died in Preston Co., (W)VA, so it's impossible for him to have had a son born in Georgia.  John & Sarah did have a son William, but this William was born in 1819/20, ten years earlier than our subject, and he married Mary BURKE. 

1.  Marriage Record:

2a.  Census Index:  U.S. Selected Counties, 1860 (Broderbund CD-318):  can't find.

2b.  1860 Census Images (online at Ancestry.com):  I went through Township 14, Calhoun Co., AL, page-by-page, and William CUPP was not found.

3.  1870 Census Images (online at Ancestry.com; Image #12 of 26):  Jacksonville P.O., Township 14, Calhoun Co., AL, p. 534A, PN 37, 263/280, enumerated 8 Aug 1870 (extracted by Diana Gale Matthiesen):

Cupp William	40	M	W	Farmer			Ga
Margaret	30	F	W	Wife			Ala
Nancy	10	F	W	At School			"
Becky	8	F	W	At School			"
H E	13	M	W	At School			"

The ordering of the children indicates that William had a former wife and that H.E. is her son.  Given the age disparity between William and Margaret, we would expect that he had a former wife, who would then be Henry's mother.  It also makes Margaret a more reasonable age 19 when she married William, instead of age 16, which she would have been if she were Henry's mother.

4.  Messages in the Cupp Family Genealogy Forum (online at GenForum.com).

5.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).  Has William the son of John Peter CUPP & Sarah WILHELM, which cannot possibly be correct because their son was born in 1819/20 in Virginia.