1.  F. Edward Wright.  1994.  Lancaster County, Pennsylvania Church Records of the 18th Century.  Vol. I.  Family Line Publ., Westminster, MD (Broderbund CD-166).

COCALICO REFORMED CHURCH Ephrata Township Baptisms by the Rev. John George Wittner...

1767... John Jacob of Conrad Kopf, Luth. and Mary Magdalene, b. December 14, 1766, bapt. January 9, 1767.  Spon: Joseph Gehr, Luth...

2.  1790 Census Index/Images (online at Ancestry.com):  can't find, but the 1790 census of Virginia was destroyed, which suggests that may have been where he was (the PA census is extant).

3.  1800 Census Index/Images (online at Ancestry.com):  can't find, but the 1790 census of Virginia was destroyed, which suggests that may have been where he was (the PA census is extant).

4.  1810 Census Index/Images (online at Ancestry.com):  can't find.

5.  1820 Census Index and Digital Images (online at Ancestry.com; Image #8 of 53; extracted by Diana Gale Matthiesen):¤•

1820

VA

Rockingham Co.

Roll M33_139

p. 127A

Ln. 4

Cupp Jacob

110001-02000-0-002

no slaves

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	9 or under	1810-1820	=
1 male	10-15	1804-1810	=
1 male	45 or over	in or bef. 1775	= Jacob (b. 1766)
2 females	10-15	1804-1810	= Daughter B = Daughter A
2	persons engaged in commerce

Is George there, but in the wrong age class?  Or is he working out?  He 

6.  1830 Census Index/Images (online at Ancestry.com, Image #X; extracted by Diana Gale Matthiesen):

1830

-

- Co.

- Twp.

Roll -

p. -

Ln. -

-

-

-

These data indicate:

7.  1840 Census Index and Digital Images (online at Ancestry.com; Image #15-16 of 178; extracted by Diana Gale Matthiesen):¤•

1840

VA

Augusta Co.

pp. 15B-16A

George W Cupp

010 201 000 100 - 222 001 000 000

0300000

no slaves

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	5-9	1830-1835	= grandson
2 males	15-19	1820-1825	= grandson = grandson
1 male	30-39	1800-1810	= son George (b. 1800)
1 male	70-79	1760-1770	= Jacob (b. 1766)
2 females	4 or under	1835-1840	= granddaughter = granddaughter
2 females	5-9	1830-1835	= granddaughter  = granddaughter
2 females	10-14	1825-1830	= granddaughter = granddaughter
1 female	30-39	1800-1810	= daughter-in-law
3	persons engaged in agriculture

Widower Jacob is living with his son, George.

8.  1850 Census Index/Microfilm (online at GenealogyLibrary.com):  56½ District, Rockingham Co., VA, p. 197, 366/375, enumerated 7 Nov 1850 (extracted by Diana Gale Matthiesen):

George Cupp	50	m	Miller		Va
[George's wife and children]
Jacob   "	83	m			"

Jacob was born in PA, not VA.

9a.  Cemetery Along the South Fork of the Shenandoah at Port Republic, Virginia (reading taken 13 May 1997 by Bill Davis, online in the USGenWeb Archives):

Jacob Cupp Who was born  Dec’r 14 1767 In Lancaster Co PA Jan 12 1852 Aged 84 yrs & 29 days

9b.  Cupp Tombstones: Jacob Cupp, Port Republic, Virginia [link died] (photo taken by Bill Sturdivant; online at Nelda Percival's genealogy web site).

In Memory of JACOB CUPP Who was born Dec'r 14, 1767 in Lancaster, PA &  Died Jan' 12, 1852 AGED 84 YEARS & 29 DAYS

Neither of the above is a verbatim reading of Jacob's tombstone, as can be seen in the photo.  Unfortunately, the stone is too shaded in the photograph to make a confident reading from it.  However, the two readings agree on the birthyear, which is the issue.

9c.  Birthdate calculated using Ben Buckner's JavaScript Birthday Calculator.

Name	Deathdate	Age at Death	Result
Jacob CUPP	12 Jan 1852	29d 0m 84y	14 Dec 1767

Jacob's baptismal record has him born 14 Dec 1766, not 1767, so he was 85 years old, not 84, when he died, which is supported by the fact that Jacob was 83 in the 1850 census.  It's far more likely that the error was made by the person ordering the stone, than that the baptismal record is incorrect, though Wright's published transcription of the record could be in error.

10.  Archives of the CUPP-L mailing list (online at RootsWeb.com).