According to Sylvia Fitts Getchell's "Fitts Families (Fitts-Fitz-Fittz), a Genealogy" your Peter Fitz' parents were Peter & Mary (Bents) Fitz.Peter was born ca. 1788.Peter and Mary (Polly) were married in the Reformed Church, York on 28 May 1812.Peter died31 March 1856 and Mary died 13 Feb. 1856.There are several entries in York County records mentioning his name in deeds and mortgages.
Your Peter's grandfather was Frederick Fitz. Frederick was born ca. 1750-55.There are numerous entries in York County records dealing with deeds, taxes etc.His wife was Elizabeth, last name unknown. Frederick died sometime between 1815-1817.His will was dated 17 May 1815 and was probated 12 March 1817.
While there is no proof, it is thought that Frederick's father may have been Johan Peter Fitz who arrived in Philadelphia in 1750 from Germany.