1.  Marriage Record:

2.  Census Index:  Colonial America, 1607-1789 (Broderbund CD-310):  not found.

3.  1790 Census Index/Images (online at Ancestry.com; Image #1 of 10; extracted by Diana Gale Matthiesen):

1790

PA

Philadelphia Co.

Germantown Twp.

Roll M637_9

p. 302

Ln. 19

Peter Stroup

1-1-3-0-0

These data indicate:

Gender and Type	Age Class	Therefore Born	Individuals Inferred
1 free white males	16 or over	in or bef. 1774	= Peter
1 free white males	15 or under	1774-1790	= Son A
3 free white females	all ages	in or bef. 1790	= Mary = Daughter A = Daughter B

This is the only Peter STROUP found in Philadelphia County in 1790, and there's no Peter STROUP found in Philadelphia County in the 1800 census, at all, so presumably this is our subject.

4.  1800 Census Index/Images (online at Ancestry.com; Image #6 of 12; extracted by Diana Gale Matthiesen):

1800

PA

Philadelphia Co.

Germantown Twp.

Roll M32_42

p. 127

Ln. 252

Mary Stroup

10000-10101-00

These data indicate:

No. & Sex	Age Class	Therefore Born	Individuals Inferred
1 male	9 or under	1790-1800	= Son A or B
1 female	9 or under	1790-1800	= Daughter B or C
1 female	16-25	1774-1784	= Daughter A or B
1 female	45 or over	in or bef. 1755	= Mary

There is no other STROUP widow in Germantown in 1800, nor did the only other STROUP male who was in the 1790 census of Germantown disappear, as did Peter.

5.  1810 Census Index/Images (online at Ancestry.com):  Mary not found.
 

.  Peter D. Keyser.  1885.  "A History of the Upper Germantown Burying-Ground."  Pennsylvania Magazine of History and Biography IX: 82-88 (reprinted by Genealogical Publ. Co., Baltimore, MD; Broderbund CD-172):

p. 560	Whereas necessity as well as saving a constant charge of supporting a wooden fence or Inclosure requires the entire closing in of the Upper Germantown Burying Ground with a stone wall round the back part thereof equal withe the other wall of the same, and as the said work is for the benefit of the Publick, and requires a sufficient sum of money for that purpose should be raised, We the subscribers do therefore hereby our subscriptions promise and bind ourselves severally to pay each of us on demand towards the said work each his subscription money or sum as is subscribed to our respective names when demanded by the collector of the same for the purpose aforesaid.—Dated, Germantown, April 11th, 1760...
p. 561	Peter Straub 0£-7s-0d... All settled Oct. 4th, A.D. 1760. All of the above-named subscribers of two shillings and upwards have a right of burial in the said Burying Ground for themselves and their family, so that they always contribute towards the necessary repairs of the enclosure and appurtenances of sd Burying Ground."
p. 568	1793.—Fourteen interments. Jan'y 22. Peter Stroup...

The question here is whether the Peter STRAUB subscribing in 1760 is the Peter STROUP interred in 1793.  I suspect so.

.  F. Edward Wright.  1994.  18th Century Records of the Germantown Reformed Church of Pennsylvania (Broderbund CD-166):

Germantown Reformed, Burial Records... List of Deceased... by L. F. Herman, p.t., 1790-1799... Peter Straub, 64 years, 10 months, 16 days old, died January 20, 1793, buried January 22, 1793.

.  Birthdate calculated using Ben Buckner's Birthdate Calculator.

Name	Deathdate	Age at Death	Result
Peter Straub	20 Jan 1793	16d 10m 64y	4 Mar 1728
(Calculated birthdates should always be prefaced with "ca." — you can't be certain the person who calculated their age did it correctly.)

-

.  Revolutionary War Soldier Graves: Burials in Bucks, Chester, Delaware, Montgomery & Philadelphia County (online at the Sons of the American Revolution: Pennsylvania Society web site, www.sar.org):

Patriot		State of Service	County of Burial	Cemetery	Rank	Birth	Death	Grave	Patriot Index
Peter	STROUP	PA	Philadelphia	Axs Cem (Upper burial Grounds)	Soldier	unk	1793	unk	-

.  Philadelphia Area Cemeteries (at Loretta Wallace's web site):

Axe's Burial Ground Germantown Ave. & Washington Lane

.  Philadelphia PAGenExchange Cemetery List (online at www.genexchange.org):

Axe's Burial Ground, Philadelphia Address: Germantown Ave. & Washington Lane, Philadelphia, PA