— born in Pike Co., IL:
  2.  Rachael MAYO, b. 1832/3; m. Nathan REED (4 Jan 1828, DE - 21 Feb 1888, Daviess Co., MO)
  3.  John J. MAYO, b. 1835/6; m. 16 Feb 1860, Pike Co., IL, Mary E. TURNER
  4.  Robert MAYO, b. 1836/7
  5.  James H. MAYO, b. 1837/8; m. 23 Oct 1873, Pike Co., IL, Margaret A. WILKINS
  6.  William H. MAYO, b. 1840; m. 23 Sep 1869, Pike Co., IL, Mary LINDSEY
  7.  Hugh L. MAYO, b. 1842/3
  8.  Charles A. MAYO, b. 1844/5
  9.  Minerva J. MAYO, b. 1846/7
10.  Joseph K. MAYO, b. 1848/9; m. 14 Apr 1872, Pike Co., IL, Hettie L. COBB

1.  Illinois Statewide Marriage Index, 1763–1900 (online at the Illinois State Archives web site):

MAYO, John J	TURNER, Mary E	02/16/1860	Book A, p. 9	Lic#2601	Pike Co.
MAYO, William H	LINDSEY, Mary	09/23/1869	Book A, p. 172	Lic#0817	Pike Co.
MAYO, Joseph K	COBB, Hettie L	04/14/1872	Book A, p. 212	Lic#0623	Pike Co.
MAYO, James H	WILKINS, Margaret A	10/23/1873	Book A, p. 235	Lic#1021	Pike Co.

2.  1840 Census Index/Images (online at Ancestry.com, Image #57-58 of 128 — indexed "Magot"; extracted by Diana Gale Matthiesen):

1840

IL

Pike Co.

Roll 67

pp. 119B-120A

Ln. 25

W J Mayot

210 001 - 020 010

0100000

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 males	4 or under	1835-1840	= James (b. 1837/8) = Robert (b. 1836/7)
1 male	5-9	1830-1835	= John (b. 1835/6)
1 male	30-39	1800-1810	= Wiley (b. 1809/10)
2 females	5-9	1830-1835	= Rachel (b. 1832/3) = Elizabeth (b. 1831/2)
1 female	20-29	1810-1820	= Rebecca (b. 1814/5)
1	person employed in agriculture

3.  1850 Census Every-Name-Index/Images (online at Ancestry.com, Image #29-30 of 45):  T3S.R2W, Pike Co., IL, Roll M432_124, pp. 48B-49A, 364/368, enumerated 18 Sep 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

Wiley J Mayo	40	M		Farmer		Tenn
Rebecca   "	35	F				Do
Elisabeth "	18	F				Do
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Rachael Mayo	17	F				Ills
John      "	14	M				Do
Robert    "	13	M				Do
James H   "	12	M				Do
William H "	10	M				Do
Hugh L    "	7	M				Do
Charles A "	5	M				Do
Minerva J "	3	F				Do
Joseph K  "	1	M				Do

4.  1860 Census Every-Name-Index/Images (online at Ancestry.com):  not found.

5.  Broderbund.  World Family Trees.  Vol. 89, Pedigree #174:  shows wife of Wiley MAYO as Rebecca NATION and husband of Rachel MAYO as Nathan REED; nothing further on Wiley or Rebecca.