Hello:
I put in the information for Joshua Arnold, b. 1828, holmes Co., OH. I found him beginning with the 1850 census with wife Sarah:
1850 Fayette, IL:
John Arnold M 49y, b. MD
Sarah Arnold F 43y, b. O
Joshua Arnold M 22y
Shelden Arnold M 19y
John Arnold M 17y
Matilda Arnold F 11y
Isaac Arnold M 9y, b. ILL
Susan Arnold F 7y
George Arnold M 4y
Sarah Arnold F 1y
According to this census John says he was born in Maryland. He is a farmer with property value of $1,000.

1870 Sefton Twp., Fayette Twp., ILL:
Joshua Arnold M 43y
Sarah Arnold F 40y
Wilson Arnold M 19y
Henrietta Arnold F 17y
Jane Arnold F 14y
John Arnold M 12y
Martha Arnold F 10y
Margaret Arnold F 8y
Chas Arnold M 5y
Frances Arnold M 3y
Nathan Hibbit M 19, farm hand
This would be John's son Joshua and his wife Sarah. Apparently both father and son married a Sarah.

1880 Sefton Twp., Fayette Co., ILL:
Joshua Arnold M 52
Spouse Sarah Arnold F 49
Child John Arnold M 21
Child Martha Arnold F 19
Child Margret Arnold F 17
Child Minnie Arnold F 12
Child Joseph D. Arnold M 10
Child Edward H. Arnold M 8
Child Benjamin F. Arnold M 6
Isaac Arnold M 17 (nephew)

What is interesting is that he lists his father's birthplace as Maryland. His wife lists her parents as being from (father) Ohio, (mother) Tennessee. This marriage had to have taken place in Ohio.

1900 Otego Twp., Fayette Co., ILL:
Joshua Arnold M , he is born in Feb 1828
Spouse Sarah Arnold F, she is born in Oct 1830

1910 Otego Twp., Fayette Co., ILL:
Joshua Arnold M 82y
Spouse Sarah Arnold F 79y
He says his father and mother were born in Maryland. This is probably where he and Sarah died as no listings for either in 1920s.

Death Certificates in Illinois listing Joshua Arnold as their father:
Name: Henry Edward Arnold
Titles and Terms (original):
Death Date: 01 Jul 1938
Death Place: Sefton, Fayette, Illinois
Gender: Male
Marital Status:
Race or Color:
Age: 66
Estimated Birth Year: 1872
Birth Date: 15 Mar 1872
Birthplace: Sefton Twp., Fayette Co., Ill.
Father: Joshua Arnold
Father's Titles and Terms (original):
Father's Birth Place: Ohio
Mother:
Mother's Titles and Terms (original):
Mother's Birth Place:
Occupation: Retired Farmer
Residence: Brownstown, Sefton, Fayette, Illinois
Street Address:
Spouse: Maude E. Arnold
Spouse's Titles and Terms (original):
Spouse's Birthplace:
Burial Date: 03 Jul 1938
Burial Place: Sefton, Fayette, Illinois
Cemetery:
Informant:
Additional Relatives:
Digital Folder Number: 4008483
Image Number: 888
Film Number: 1818884
Volume/Page/Certificate Number: 26187

Name: Salina J. Flowers
Titles and Terms (original):
Death Date: 07 Jul 1941
Death Place: Brownstown, Fayette, Ill.
Gender: Female
Marital Status:
Race or Color:
Age: 85
Estimated Birth Year: 1856
Birth Date: 12 May 1856
Birthplace: Fayette, Ill.
Father: Joshua Arnold
Father's Titles and Terms (original):
Father's Birth Place: Ohio
Mother: Sarah Workman
Mother's Titles and Terms (original):
Mother's Birth Place: Ill.
Occupation: Housewife
Residence: Brownstown, Otego, Fayette, Ill.
Street Address:
Spouse: Samuel Flowers
Spouse's Titles and Terms (original):
Spouse's Birthplace:
Burial Date: 10 Jul 1941
Burial Place: Sefton, Fayette, Ill.
Cemetery: Liberty
Informant:
Additional Relatives:
Digital Folder Number: 4008580
Image Number: 1468
Film Number: 1851209
Volume/Page/Certificate Number: cn 13

Here is an interesting one from Holmes Co., OH. Must be some connection somehow:
Name: Clifford Arnold
Titles & Terms:
Event: Death
Event Date: 07 Jan 1918
Event Place: Killbuck Twp, Holmes, Ohio
Residence:
Street Address:
Gender: Male
Death Age: 21y 6m 13d
Marital Status: Single
Race: White
Occupation: School Teacher
Birth Date: 22 Jun 1896
Birthplace: Ohio
Estimated Birth Year: 1897
Burial Date: 09 Jan 1918
Burial Place: Killbuck, O
Cemetery:
Father: Joshua Arnold
Father's Titles & Terms:
Father's Birthplace: Ohio
Mother: Jennie Conkle
Mother's Titles & Terms:
Mother's Birthplace: Ohio
Spouse:
Spouse's Titles & Terms:
Reference Number: fn 3787
Film Number: 1984227
Digital Folder Number: 4021709
Image Number: 842

Marriage for the above Arnold:
Groom's Name: Joshua Arnold
Groom's Birth Date:
Groom's Birthplace:
Groom's Age:
Bride's Name: Jennie Conkle
Bride's Birth Date:
Bride's Birthplace:
Bride's Age:
Marriage Date: 25 Dec 1892
Marriage Place: , Holmes, Ohio
Groom's Father's Name:
Groom's Mother's Name:
Bride's Father's Name:
Bride's Mother's Name:
Groom's Race:
Groom's Marital Status:
Groom's Previous Wife's Name:
Bride's Race:
Bride's Marital Status:
Bride's Previous Husband's Name:
Indexing Project (Batch) Number: M86934-2
System Origin: Ohio-VR
Source Film Number: 477146
Reference Number: 2:3J225VW

I'm including this marriage as being interesting to you. Please look at where they say the marriage took place:
Groom's Name: Joshua S. Arnold
Groom's Birth Date:
Groom's Birthplace:
Groom's Age:
Bride's Name: Martha Powell
Bride's Birth Date:
Bride's Birthplace:
Bride's Age:
Marriage Date: 24 Jan 1843
Marriage Place: Allegany,Maryland
Groom's Father's Name:
Groom's Mother's Name:
Bride's Father's Name:
Bride's Mother's Name:
Groom's Race:
Groom's Marital Status:
Groom's Previous Wife's Name:
Bride's Race:
Bride's Marital Status:
Bride's Previous Husband's Name:
Indexing Project (Batch) Number: M53372-1
System Origin: Maryland-ODM
Source Film Number: 13310
Reference Number

Maybe that is why there is some confusion with Allegheny Co, PA. I guess there is also an Alleghey, Maryland as well.

Back to Illinois Death Certificates:
Name: Martha Naoma Cox
Titles and Terms (original):
Death Date: 20 May 1938
Death Place: Chicago, Cook, Illinois
Gender: Female
Marital Status:
Race or Color:
Age: 77
Estimated Birth Year: 1861
Birth Date: 16 Dec 1860
Birthplace: Brownstown, Ill
Father: Joshua Arnold
Father's Titles and Terms (original):
Father's Birth Place:
Mother: Sarah Workman
Mother's Titles and Terms (original):
Mother's Birth Place:
Occupation: Housewife
Residence: Chicago, Cook, Ill.
Street Address:
Spouse: Frank
Spouse's Titles and Terms (original):
Spouse's Birthplace:
Burial Date: 23 May 1938
Burial Place: Chicago, Cook, Ill
Cemetery: Rosehill
Informant:
Additional Relatives:
Digital Folder Number: 4205892
Image Number: 1951
Film Number: 1953319
Volume/Page/Certificate Number: rn 14202

According to the Green/MacAlpine Family Tree, they have the above John Arnold and family as:
John Arnold
Birth 1801 in Allegany County, Maryland, USA
Death

Sarah Kern 1806 –

Joshua Arnold 1828 – 1914, Brownstown, Fayette Co., ILL with wife Sarah Workman, Liberty Cemetery
Sheldon Arnold 1831 –
John Arnold 1833 – 1880
Matilda Arnold 1839 – 1912
Isaac Arnold 1841 –
Susan Arnold 1843 –
George W. Arnold 1846 – 1923
Sarah Arnold 1849 –

Joshua & Sarah Workman Arnold, they list their children as :
Sarah Workman 1830 – 1925

Wilson S Arnold 1852 – 1900
Henrietta Arnold 1853 –
Jane Arnold 1856 –
John Arnold 1859 –
Martha Arnold 1861 –
Margret Arnold 1863 –
Charles Arnold 1865 –
Frances Arnold 1867 –
Minnie Arnold 1868 –
Joseph D Arnold 1870 –
Edward H Arnold 1872 –
Benjamin F Arnold 1874 –

The researcher from the above information is Shannon MacAlpine. I noticed that someone known as Irish Princess working on a McDonald family line originally submitted the picture of the tombstone. Jackson Welch working on an ARnold family line and a Bennett7278 working on a Lawson family line all saved the tombstone pic to their trees. So more connections for you. Shannon has no father or mother listed for John Arnold or Sarah Kern

I'm including a link for a John Arnold tombstone found in the Yolton Cemetery, Avena, Fayette Co., ILL. If it is the same John Arnold, then he was married for a second time to a Sabina M. Arnold? Could be a mistake on the part of the tombstone transcriber. You'll have to check it out and see what you think:

http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=61...

Tombstone for George W. Arnold (he was also in the Civil War so there should be pension records you could order):

http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=Ar...;

George's wife Martha J. link:
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GSln=Ar...;

Joshua & Sarah Arnold are buried in the same cemetery as George W. was buried in the Old Liberty Cemetery. They don't have pics of their tombstones but you can request them to be taken.

Joshua's link
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=48...

Sarah's link
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=48...

Charles W. Arnold link (died as a teenager):
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=48...

Melvina Arnold's link (died as an infant):
http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=48...

There are others but you can go to the site and look them up.

Here is a list of Pre-1916 Arnold deaths in Fayette co., ILL:

ARNOLD, CHARLES 1878-09-06 SEFTON TWP 15 YR M 1 13 FAYETTE
ARNOLD, JOSHUA 1914-12-07 BROWNSTOWN 86 YR M 3 270 734 FAYETTE
ARNOLD, RHODA 1879-07-12 LOUDON TWP UNK F 1 29 FAYETTE
ARNOLD, RHODA 1902-05-19 BROWNSTOWN 05 YR F 1 162 FAYETTE
ARNOLD, UNKNOWN 1904-11-00 SEFTON TWP 05 DA M 2 95 285 FAYETTE
ARNOLD, WILLIAM H 1902-10-01 HAGERSTOWN 01 MO M 1 181 FAYETTE
ARNOLD, WILLIAM S 1880-10-12 SEFTON TWP 12 YR M 1 50 FAYETTE

After 1916 Arnold Deaths in Fayette County, ILL:
ARNOLD CYRUS E M/W Y-72 0000233 1942-11-06 FAYETTE VANDALIA - -
ARNOLD E M M/W UNK 0015526 1918-05-24 FAYETTE SEFTON TWP 18-08-02
ARNOLD FERN F/W UNK 0260111 1926-05-13 FAYETTE KASKASKIA TWP 26-05-17
ARNOLD FLORENCE F/W UNK 0260226 1925-11-15 FAYETTE KASKASKIA TWP 25-11-16
ARNOLD GEORGE W M/W UNK 0260131 1922-03-19 FAYETTE SEFTON TWP 22-03-21
ARNOLD HARRIETT F/W UNK 0000108 1940-04-26 FAYETTE VANDALIA - -
ARNOLD HAZEL N/S UNK 0046885 1944-12-09 FAYETTE VANDALIA - -
ARNOLD HENRY E N/S UNK 0000143 1938-07-01 FAYETTE - -
ARNOLD ISAAC M/W Y-78 0000077 1941-04-02 FAYETTE ST ELMO - -
ARNOLD JAMES HARVEY M/W UNK 0015774 1920-03-17 FAYETTE SEFTON TWP 20-03-29
ARNOLD LELAND EARL M/W UNK 0012678 1917-06-15 FAYETTE SEFTON TWP 17-07-23
ARNOLD MARTHA JANE F/W UNK 0012719 1917-08-02 FAYETTE SEFTON TWP 17-09-12
ARNOLD MARY AMELIA F/W UNK 0260281 1924-12-30 FAYETTE ST ELMO 24-12-31
ARNOLD MARY ANN F/W UNK 0033245 1920-09-13 FAYETTE LOUDON TWP 20-10-12
ARNOLD MAUDE E N/S UNK 0000166 1938-08-15 FAYETTE - -
ARNOLD ROBERT DWANE M/W UNK 0260274 1931-10-10 FAYETTE LOUDON TWP 31-10-11
ARNOLD SARAH F/W UNK 0260115 1925-05-13 FAYETTE BROWNSTOWN 25-05-13

Marriages 1763-1900 for Arnolds in Fayette Co., ILL:
ARNOLD, CHARLES BULLINGTON, RHODA E 1893-12-24 A/ 312 FAYETTE
ARNOLD, CHARLES MOREY, SYPHA MAY 1897-03-24 B/ 66 FAYETTE
ARNOLD, EDGAR M DIVELY, MARY 1893-11-26 A/ 311 FAYETTE
ARNOLD, GEORGE BUMGARDNER, ANGELINE 1847-04-08 00A/0029 FAYETTE
ARNOLD, GEORGE SMITH, MARTHA J 1867-12-12 00A/0107 FAYETTE
ARNOLD, GEORGE N COLE, LUCY 1857-10-01 00A/0061 FAYETTE
ARNOLD, H E WILLIAMS, MAUDE (WILLMS) 1893-05-21 A/ 301 FAYETTE
ARNOLD, HENRY S SMITH, RACHEL S 1855-02-25 00A/0090 FAYETTE
ARNOLD, ISAAC W MORRISON, IDA M 1887-12-11 A/ 200 FAYETTE
ARNOLD, JOHN HANES, MARY J 1856-10-19 00A/0057 FAYETTE
ARNOLD, JOHN RICE, SABINA 1854-03-19 00A/0019 FAYETTE
ARNOLD, JOHN W YALTON, GENEVA E 1882-11-30 A/ 103 FAYETTE
ARNOLD, JOSHUA WORKMAN, SARAH 1851-04-24 00A/0041 FAYETTE
ARNOLD, LEVI SLOAN, CLARISSA T 1873-07-14 00A/0135 FAYETTE
ARNOLD, SAMUEL FLEMMING, JANE 1855-03-18 00A/0052 FAYETTE
ARNOLD, SAMUEL TOMPKINS, MATILDA 1849-06-07 00A/0035 FAYETTE
ARNOLD, W L ANDERSON, JULIA 1866-05-24 00A/0097 FAYETTE
ARNOLD, WILLIAM DIAL, LUCY 1893-12-24 A/ 312 FAYETTE
ARNOLD, WILLIAM MORGAN, EDITH MAUDE 1897-10-03 B/ 76 FAYETTE
ARNOLD, WILSON S BOWMAN, MARY A 1876-10-22 00B/0013 FAYETTE

Joshua & Sarah Workman were married in ILL not Ohio.

Hope this helps.
Leslyn