Hiram was called "Sloan Hill" in the 1850 census with his parents, so he was obviously named for his maternal grandfather.  He was orphaned while still a young child, so I wonder if he had mis-heard or mis-remembered "Logan" and inadvertently changed his middle name to "Morgan" (or if his foster/adopted parents made the error).

Diana is said to be born in 1859, but she does not appear in the 1860 census with her parents.

Secondary sources give her middle name, "Murphy," which, as her mother's surname, certainly would have been a logical assumption, but on her marriage application and marriage certificate — the only primary sources I have — she calls herself, "Diane Morgan-Hill."  Or did Diane simply arbitrarily change her name?

1.  Marriage Record:

2.  1850 Census Every-Name-Index/Images (online at Ancestry.com, Image #15-16 of 292 — middle initial indexed "N"):  District No. 14, Cape Girardeau Co., MO, Roll 394 (Book 1), pp. 348A-348B, 100/101, enumerated 10 Aug 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

Samuel A Hill	30	M		Lawyer	2500	Mo
[next page]
Julia Hill	20	F				Mo
Sloan  "	3	M				"
S A    "	4/12	F				"
George F Taucher	35	M		None		Germany

Also living in Cape Girardeau is Hiram's maternal grandfather, Hiram Logan SLOAN.

3.  1860 Census Every-Name-Index/Images (online at Ancestry.com, Image #56 of 88):  New Madrid P.O., New Madrid Co., MO, Roll M653_636, p. , PN 66, 453/453, enumerated 13 Jul 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

Isaac Hunter	39	M		Farmer	22060	19000	Mo
Ellen    Do	27	F					"
Atha     Do	14	F					"
Molly    Do	8	F					"
Amanda   Do	7	F					"
Abraham  Do	5	M					"
Franklin Do	1	M					"
Jackson Hill	14	M					"
Hiram    Do	13	M					"
Sally    Do	9	F					"

Isaac HUNTER's first wife was Susan HILL.  I don't know how she was related to Hiram, but surely she was.  "Sally" HILL is Hiram's sister, Sarah Alice/Althea; I don't know who Jackson HILL is.

4a.  1870 Census Every-Name-Index/Images (online at Ancestry.com, Image #50 of 134):  Hotel, Cape Girardeau City (Ward 1), Cape Girardeau Co., MO, Roll M593_765, p. 88B, PN 8, 56/52, enumerated 1 Aug 1850, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

Hill Alice	20	F	W	No Occupation			Mo
____ Morgan H	23	M	W	"			Mo

Alice/Althea is Morgan's sister.  They are two of 15 guests in a small hotel.

4b.  1870 Census Every-Name-Index/Images (online at Ancestry.com).  "Dannie" MURPHY (æ 9, b. CA) is living in San Jose, Santa Clara Co., CA, with her parents (q.v.).

5a.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #23 of 28):  Baldwin Hotel, Market Street, City and County of San Francisco (Ward 8), CA, Roll T9-0075, p. 260C, PN 23, SD 1, ED 83, enumerated 10 Jun 1880, official enumeration date 1 Jun 1880 (extracted by Diana Gale Matthiesen):

1880:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
	1	2	3	4	5	6	8	9	13	24	25	26
*	84	104	Hill Morgan	W	M	30	Boarder	/	Fancy Goods	MO	MD	MD
			____ S A	W	F	27	Boarder	/	At home	MO	MD	MD
*Market

S.A. is Morgan's sister, Sarah Alice/Althea.  They are two of many guests in a large hotel.

5b.  1880 Census Every-Name-Index/Images (online at Ancestry.com):  can't find Diana or her parents.

6.  1890 Census:  the 1890 Census Population Schedules were destroyed.

7.  1900 Census Every-Name-Index/Images (online at Ancestry.com):  can't find.

8.  1910 Census Index/Images (online at Ancestry.com, Image #20 of 23):  1726 N Street, Washington, District of Columbia, Roll T624_150 (Part 2), p. 155B, SN 10B, SD _, ED 55, enumerated 25 Apr 1910, official enumeration date 15 Apr 1910 (extracted by Diana Gale Matthiesen):

1910:  for an explanation of the column headings, please see What the Numbers in the Federal Census Mean (missing columns contained no data).
		1	2	3	4	5	6	7	8	9	10	11	12	13	14	17	18	19	20	23	24	25	26	27	28
*	1726	155	176	Hill Hiram M	Head	M	W	62	M1	27			Missouri	Maryland	Missouri	Eng	Proprietor	Cattle Ranch	Emp	Y	Y		O	F	H
				____ Diana M	Wife	F	W	47	M1	27	1	1	California	Canada (Eng)	Mexico	Eng	None			Y	Y
				____ Diane M	Dau	F	W	25	S				California	Missouri	California	Eng	None			Y	Y	Y
*N Street

9.  1920 Census Index/Images (online at Ancestry.com):  Hirum is deceased, can't find Diana.

10.  Mary Carroll, Ten Years in San Jose, 1892-1903 (database extracted from the works of Mary Carroll, online at Ancestry.com).

p. 33	Society in the Eighties and Nineties...  The first social function of any magnitude was the golden wedding of two of this county's most respected pioneers, Mr. and Mrs. Martin Murphy. The scene of the festivities was at the Murphy home near Mountain View.  No invitations had been issued, but the doors of the hospitable home were opened for all who chose to enter, and upward of four thousand were entertained... About this time the ladies came forward and took an active part in social matters, and the result was the organizing of the "Young Ladies' Social Temperance Club"...
p. 34	Among its members were the following names...
p. 35	...Miss Diana Murphy, now Mrs. Morgan Hill of Paris...

11.  Beth Wyman.  1983.  Hiram Morgan Hill.  Self-published (printed in Morgan  Hill, CA), 50 pp.  The booklet is a good read, but lacks primary documentation for their early lives, for which the author appears to rely entirely on previously published secondary sources (listed in the bibliography).  The unfortunate consequence of depending entirely on secondary sources is that you don't recognize the errors they contain and, thus, end up perpetuating them.  In contrast to the early years, the book does include some useful documentation for their daughter and their later lives (e.g., a facsimile of Hiram's death certificate naming his parents).  The book contains numerous photos and facsimiles, which the author must have gone to considerable effort to compile and which add to the value of this little booklet.

p. 3	The author states that Morgan and Sarah Althea "grew up in the Cape Girardeau home of their paternal grandparents."  The problem is, their paternal grandparents died in 1850/51, before their parents died in 1853/54; and their maternal grandparents died in 1841/55.  One could interpret that the author only meant they lived in the house owned by their paternal grandparents, except that she later writes that the grandmother evicted Hiram from the house at the age of 22 because he'd fallen in love with a cousin and that this was the reason he went to San Francisco.  It's a romantic tale, but clearly a "tall tale," because both of Hiram's grandmothers had died by the time he was in grade school.  Also, the 1860 census shows Hiram and his sister living with (uncle?) Isaac HUNTER in New Madrid Co., MO; and the 1870 census shows them living in a hotel in Cape Girardeau, independent of any relatives.  It may be that Isaac HUNTER evicted Hiram for lusting after one of his daughters (or that one of Isaac's daughters was hot for Hiram), but the tale, as told, simply can't be true.
p. -	-
p. -	-

12.  WorldConnect / Ancestry World Trees (online at RootsWeb.com/Ancestry.com).

13.  Marty Cheek.  Wednesday, 16 Oct 2002.  "South County Towns' Names Rich in History: Morgan Hill."  The Gilroy Dispatch, Gilroy, CA (online at www.gilroydispatch.com).

14.  Marty Cheek.  Friday, 28 Mar 2003.  "Landmark Studies: Villa Mira Monte."  The Gilroy Dispatch, Gilroy, CA (online at www.gilroydispatch.com).

15.  John Bulmer Lisle & Carolyn Miethe Lisle.  Family History Research (website online at www.tqsi.com/genealogy/).

16.  Email from Bud O'Hare of the Morgan Hill Historical Society.

17.  Numerous sites on the web.