1.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org).

Patrick NOLAN Spouse: Catharine FALEN Marriage: 28 Sep 1856, Kennebec, Maine Source: Marriage Records, ca. 1828-1887... Maine Supreme Court (Kennebec County)

2.  1860 Census Images (online at Ancestry.com; Image #58 of 59):  Winthrop P.O., Winthrop, Kennebec Co., ME, p. 1050, PN 58, 442/482, enumerated 7 Jul 1860, official enumeration date 1 Jun 1860 (extracted by Diana Gale Matthiesen):

Patrick Nolan	29	M		Oil Cloth Carpet Laborer			Ireland
Catharine "	23	F					do
Margaret  "	3	F					Maine
Timothy   "	1	M					do
Marg Fallan	25	F					Ireland

Several men on this and adjacent pages were employed in various jobs in an "Oil Cloth Carpet" factory.  Margaret FALLAN is almost certainly Catherine's sister.

3.  Family Quest Archives:  California Federal Census 1870:  Plumas and Sacramento Counties.  (Heritage Quest CD M593-77):  Sacramento 4th Ward, Sacramento Co., CA, p. 320B, PN 4, enumerated ca. 9 Jun 1870, official enumeration date 1 Jun 1870 (extracted by Diana Gale Matthiesen):

1870:  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	15	19
27	36	Hopkins Mark	54	M	W	Treasr R R Co	9150	8,655,780	New York				/
		_______ Mary F	48	F	W	Keeps House			"   "
		Nolan Timmy N	9	M	W	attends school			Maine			/
		Ah Sing	25	M	C	domestic			China	/	/

This may be a "Stella Dallas" story, with Catherine giving up her son so he could have a better life than she could ever have given him; or, on the dark side, she could have sold him or just deserted him.

4.  1880 Census Every-Name-Index/Images (online at Ancestry.com, Image #6-7 of 22):  California [St.], San Francisco, San Francisco Co., CA, Roll T9_74, pp. 701B-702C, PN 6-7, SD 1, ED 55, enumerated 2 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

11

13

24

25

26

*

42

48

Hopkins M F

W

F

52

/

Keeping house

NY

CT

MA

_______ Timothy

W

M

21

adopted son

/

At home

Calif

Calif

Calif

Crittenden May

W

F

17

Niece

/

At home

MO

NY

NY

[plus nine servants]

*California

Mary adopted Timothy, her housekeeper's son, as an adult, after the death of her husband, Mark HOPKINS, in 1878.  Timothy was born in Maine, not CA, and his parents were born in Ireland, not CA.  Timothy later married May CRITTENDEN.

5.  1890 Census:  the 1890 Census Population Schedules were destroyed.

6.  Timothy Hopkins.  1932.  John Hopkins of Cambridge, Massachusetts, 1634, and Some of His Descendants.  Stanford Univ. Press, Stanford, CA.

7.  Harold Clarke Durrell.  1936.  "Memoirs of Deceased Members of the New England Historic Genealogical Society." New England Historical and Genealogical Register 90(April): 167-194.  On p. 182:

TIMOTHY HOPKINS, of Menlo Park, Calif., adopted son of Mark and Mary Frances (Sherwood) Hopkins, elected a resident member 6 May 1896 and made a life member 18 May 1896, was born at Hallowell, Maine, 2 March 1859, the son of Patrick and Catherine (Fallon) Nolan, and died in San Francisco, Calif., 1 January 1936. His father, Patrick Nolan, born at Glenmore, co. Mayo, Ireland, in 1829, came to New England in 1852, settled at Winthrop, Maine, where he found employment in an oilcloth shop and married Catherine Fallon.  In May 1862 he left home for California to seek better fortune in the gold fields.  However, he secured work in San Francisco and sent East for his family, but he was accidentally drowned on the day that they sailed form New York. Mrs. Nolan, who later married a second time and moved to St. Louis, Mo., found work in the family of Mark Hopkins, the railroad magnate, and in a short time Timothy, now three years of age, was made a member of the family.  On the death of Mark Hopkins in 1878, he was legally adopted by the widow...