I am researching two families with similar names:
George Giesser or Von Giesse, of Sussex, now-Warren, Co., NJ.This was across the Delaware from Northampton, PA.He arr. America 1750, had 8 daus, no sons, so the name has died out and spelling varies.He appeared to come alone, without relatives. In looking for some ancestors of his, I discovered your genforum board.
A second family of interest is Kizer and variant spellings of Oxford, Sussex Co, NJ, who vanished from that area around 1810.Given names in this family were Nicholas, Henry, Jacob.Some members show up in Mt. Bethel Twp., Northampton - again, across the river.
In searching the latter, I found a similarly named family in Macungie, Lehigh (previously Northampton) and think this would probably be the one you're looking for.Here's what I found on ancestry:
Searched on "Nicholas Kiser" (because Henry and Jacob, the
other two names used in that family, were more generic) and found this good possibility in the 1830 census for Lehigh Co., Macungie Twp., PA.
In 1830 Nicholas Keyser:
1 male 60-70; 1 female 60-70 [ie, birthdate ca 1765]
In 1840, same location:
1 male 70-80; no females.
In 1830, living nearby were:
Henry Keyser, 40-50
Jacob Keyser, 30-40
George Keyser, 30-40
David Kaser, 20-30
Elias Kaser 20-30
Re:the NJ family, I have Nicholas b. 1746, and (probable) brother Jacob.They applied for Revolutionary pensions and said they were born in Bucks County, PA.Their father was probably Henry, b. abt 1720 who's listed in Sussex Co. tax book in 1773.Nicholas had a son Henry b. 1772.
If you're just starting your search, you may find this information extraneous. But I believe it might be helpful to you in several ways.First, it may indicate a common origin for both the Macungie and the NJ families, i.e., Bucks County - which is consistent with historical movements of early arrivals.Second, the given names for both families are similar.Not always, but sometimes, a good clue to a common ancestor.Note that most of the names of this period will be in the form of "Johan Nicholas" --- but the common usage will be to just use Nicholas in records, and not John or Johan. You should check under both forms, however.Third, this offers some alternative spellings for the surname which will be necessary to look under.
A side interest of mine has been to catalog all the original settlers where brothers settled on opposite sides of the Delaware river.I believe this was done intentionally, to increase the odds, in case government changed or became abusive in one or the other territory.(After all, they'd just come from 200 years of territorial upheaval along the Rhine.)
Good luck in your search,