1.  Tombstone Readings:  St. John's Church Cemetery, Freline Road, Palmerton, Towamensing Twp., [Carbon Co.,] Pa  [link died]:

Row 6... 13. Jacob Straup, son of Elias and Catharine Straup, Sept 24 1843, Sep 18 1856, 13 years less 6 days

If Jacob was born in 1843 and died in 1856, he should be in the 1850 census.  However, I can find no Elias & Catharine STRAUP with son Jacob in the 1850 census in Pennsylvania, but see the following sources.

2.  1840 Census Index/Images (online at Ancestry.com, Image #15 of 18; this enumerator did not record occupations; extracted by Diana Gale Matthiesen):

1840

PA

Schuylkill Co.

West Penn Twp.

Roll M704_492

p. 148B

Ln. 20

Elias Strouse

200 001 - 010 000 100

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
2 males	4 or under	1835-1840	= Son A = Joseph (b. 1835)
1 male	30-39	1800-1810	= Elias (b. 1800)
1 female	5-9	1830-1835	= Eliza (b. 1831/2)
1 female	40-49	1790-1800	= Catharine

This is the only Elias STRAUSS (or variation) in the entire 1840 census; there is no Elias STRAUP (or variation), at all.

3a.  1850 Census Index/Images (online at Ancestry.com; Image #16 of 37 — indexed "Strauss," but incorrectly as being on p. 380 and linked to p. 380A):  Mahoning Twp., Carbon Co., PA, p. 381B, 114/126, enumerated 19 Oct 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

Elias Strauƒs [long-s]	50	M		Farmer		Penna
Eliza	18	F				"
Eve Strauss [short-ss]	70	F			1600	"
Peggy	52	F				"	Deaf & Dumb
David	44	M		None		"	Deaf & Dumb
Isaac	30	M		None		"	Deaf & Dumb

My interpretation of this record is that Elias is a widower or divorcé, that Eliza is his daughter, that Eve is his mother, and that the rest are his siblings.  His son, Jacob, is listed four houseolds away (see next source).  He is the only Elias STRAUSS (or variation) in Carbon Co., PA.  There is no Eli/Elias STRAUP (or variation) in Carbon County.  (The Eli STROUP in Blair County is an unmarried laborer living with another family, i.e., no wife or children.)  I can't find Catharine.

3b.  1850 Census Index/Images (online at Ancestry.com; Image #14 of 37):  Mahoning Twp., Carbon Co., PA, p. 380B, 100/112, enumerated 19 Oct 1850, official enumeration date 1 Jun 1850 (extracted by Diana Gale Matthiesen):

Conrad Kaser	50	M		Farmer	1200	Penna
Rebecca	35	F				"
Jacob Strauss [short-ss]	7	M				"
Joseph Straus [short-s]	15	M		Farmer		"

This Jacob appears to be the son of Elias who later died and is buried in St. John's Cemetery.  Joseph also appears to be a son of Elias.

4.  1860 Census Images (online at Ancestry.com; Image #44-45 of 50):  Mahoning Twp., Carbon Co., PA, pp. 974-975, PN 65-66, 443/320, enumerated 27 Jun 1860 (extracted by Diana Gale Matthiesen):

Moses Rex	24	M		Mason	1500	400	Pa
Sarah	23	F					"
[next page]
[Moses & Sarah's children]
Salome Joyman	50	F					"
Cath Straup	54	F					"	Pauper

Is this Catharine, wife of Elias?

5.  1870 Census Images (online at Ancestry.com; Image #30 of 40):  Lehighton P.O., Mahoning Twp., Carbon Co., PA, p. 179B, PN 30, 208/224, enumerated 1 Aug 1870 (extracted by Diana Gale Matthiesen):

Fryman Thomas	34	M	W	Farmer		500	Pa
______ Susan	31	F	W	Keeping House			Pa
[Thomas & Susan's children]
Strous Catharine	66	F	W	At Home			Pa