If Daniel OBORN and his brother were born in Huntingdon Co., PA, as is said, then there appear to be only two possibilities for their father, namely, James OBURN and Joseph OBURN, for they were only two OBURNs in Huntingdon Co., PA, in the 1790 census.  In fact, aside from an OBURN in New York, James and Joseph were the only OBURNs/OBORNs in the entire 1790 census.  In the 1800 census, Joseph has no son the right age to be these two boys, so he is not the father, leaving only James, but James disappears from the census, not to be found again.  It also appears that James must have died by 1800, leaving the two boys (and their siblings) orphans.  Given the nature of the early censuses, we cannot tell whether they are living with their widowed (and possibly re-married) mother or with other kin. 

4.  Joseph OBORN, b. ca. 6 Jul 1791, PA 
5.  Daniel OBORN, b. 30 Jun 1794, Huntingdon Co., PA 

1.  LDS.  Family Search: Internet Genealogy Service:  IGI - International Genealogical Index (online at FamilySearch.org).

James OBURN Birth: 1765, Huntingdon, Pennsylvania Spouse: Mrs. James OBURN Birth: 1768, Huntingdon, Pennsylvania Source: patron submission

Huntingdon County was not formed (from Bedford County) until 1787, so our subjects could not have been born in that location under that name.  But the location does indicate that the source must have been referring to the James OBURN who does show up in Huntingdon County in the 1790 census.  I don't know how much confidence to place in the birthdates, but for now I'm going to assume they are correct, or at least nearly so.

2.  Census Index:  Colonial America, 1607-1789 (Broderbund CD-310):  there is no OBORN or OBURN on the CD, and the surnames that could be mis-readings of OBORN appear to be German — our subject is said to be Scottish.

3.  1790 Census Index/Images (online at Genealogy.com; Image #11 of 12; extracted by Diana Gale Matthiesen):

1790

PA

Huntingdon Co.

Roll 8 (Book 2)

p. 131

Ln. 46

James Oburn

1-1-3-0-0

These data indicate:

Gender and Type	Age Class	Therefore Born	Individuals Inferred
1 free white male	16 or over	in or bef. 1774	= James (b. 1765)
1 free white male	15 or under	1774-1790	= Son
3 free white females	all ages	in or bef. 1790	= Wife (b. 1768) = Daughter = Daughter

James is the only OBURN/OBORN indexed on the CD (aside from an OBURN in NY), but the elder "Joseph Obom" indexed in Huntingdon County appears in later censuses to have been "Joseph Oborn," and is presumably James's father or older brother.

4.  1800 Census Index/Images (online at Ancestry.com):  James is not found, and Joseph OBURN, in Huntingdon Co., PA, is the only OBURN/OBORN indexed on the CD.