We know four Berry's  listed in the 1790 Orange  County Census
Robert Berry Sr.
Robert Berry Jr.
Joshua Berry
John Berry father of the  John Berry the architect who was under 10 years old in the1800 Census.

We know that  eight Berry's listed in the 1800 census.
Robert Berry Sr.
Robert Berry Jr.   (son of Robert Berry  Sr.)
Joshua Berry        (son of Robert Berry Sr.)
Thomas Berry       (son of Robert Berry Sr.)
William Berry        (son of Robert Berry Sr.)
David Berry          (son of Robert Berry Sr.)
James Berry          (Most likely son of Robert Berry Jr. or Joshua Berry)
Roda Berry          Widow of John Berry listed one male under 10 years old (John Berry the Architect)

Robert Berry Jr. listed in the 1800 Orange county Census
I male 16 to 26
1 male 45 and up
1 female 10 to 16
1 female 26 to 45
1 female  45 and up

Joshua Berry listed in the 1800 Orange County Census
3 males under 10
1 male 10 to 16
1 male 26 to 45
2 females under 10
1 female 26 to 45
1 female 45 and up

These two Census enumerations  of Joshua and Robert Berry Jr. leads me to believe that Robert Berry Jr. was the oldest son of Robert Berry Sr. I think Joshua was the second son from his name (naming patterns)and the enumeration of the 1800 Orange County Census.

We know that there were six Berry. families to list in the 1810 Orange County Census.
Robert Berry (no Sr. denoted in this listing indicating that Robert Berry Jr had died or removed from the County)
2 males 26 to 45 (Henry and Issac)
1 male 45 and up Robert Berry Sr.
1 female 45 and up Elizabeth Cates Berry wife of Robert Berry Sr.
There was no Robert Berry Sr. denoted in the 1810 Census which probably means that Robert Berry Jr. had removed for Orange County 
North Carolina . We know that Robert Berry Jr was still alive in 1812 when Robert Berry Sr. wrote his will.

1810 census
B Berry  (could be the son of Robert Berry Jr.)
2 males under 10
1 male 26 to 45
2 females under 10
1 female 26 to 45

The other Berry families in the 1810 Orange County Census were:
Hannah Berry (Grass widow of William Berry),
J Berry,
David Berry
Roda Berry****** widow of John Berry and mother of John Berry the Architect

In the 1820 Orange County Census  There were five Berry families listed
Henry Berry (Robert Sr Died in 1814)
Robert Berry whose oldest male was 25 to 45 (not Robert Berry Jr.)
Joshua Berry
David Berry
Roda Berry ******widow of John Berry and mother of John Berry the Architect

In summery Robert Berry Jr disappeared from Orange County by 1810 but was not dead in 1812
 he was not listed as deceased  in his fathers will.
In 1850 when the enumeration stated children's names and ages. I found only one Berry family that was not related to
Joshua or William Berry.
This family was John Berry the Architect

I have never found a marriage bond on Robert Berry Jr. and I simply do not know where his family is. He could be in Person County
but I have made a feeble search there and have not found him.
This is one area that I need to research further