Your Samuel Graul (who was, as it happens, the nephew of my Samuel Graul) was born on 28 Jun 1801.He was the son of Johann Graul of Reading and his second wife, Mary Byerle, who were married on 1 Jan 1799.
Johann Graul was born in Berks County about 1773 and died in Reading on 15 Dec 1850.He was the son of Johan Jacob Graul and Catherine Christ who were married in Reading on 27 Sep 1770.
Jacob Graul was born in Heuchelheim, Frankenthal, Pfalz on 2 Jan 1731 and died in Reading on 19 Jul 1811.He was the son of Johan Michael Graul and Sybilla Elizabetha Fulman, who were married in Heuchelheim on 8 Jul 1724.
Johan Michael Graul was born c. 1683 in Germany and died prior to 31 Jan 1774 in Berks County.Sybilla was born 6 Feb 1704/5 in Heuchelheim and died prior to 4 Apr 1776 in Reading.She was the daughter of Johan Jacob Fulman and Anna Barbara Siegfried, who were married in Heuchelheim on 30 Jan 1703.
Johan Jacob Fulman was born 22 Dec 1681 in Heuchelheim and died 14 Feb 1753 in Pennsylvania.Anna Barbara was born about 1683 in Heuchelheim and died prior to 6 Jun 1756 in Pennsylvania.
Catherine Christ was born 2 Feb 1753 in Berks County and died 12 Oct 1801 in Berks County.She was the daughter of Johannes Heinrich Christ and Appolonia Richter, who were married 25 Jan 1748 in Richmond, Berks County.
Johannes Heinrich Christ was born 26 or 27 Jan 1721 in Hatten, Hanau-Lichtenberg, Alsace and died 13 Aug 1789 in Reading.He was the son of Johannes Heinrich Christ, Sr. and Anna Gotz, who were married 8 Jan 1715 in Hatten.
Johannes Heinrich Sr. was born about 1690 in Bern, Switzerland and died after 25 Jan 1748 in Maxatawny Township, Berks County.Anna was born about 1690 and died after 11 Sep 1732.
Appolonia Richter was born around Jan 1721 and died 8 Jul 1805 in Reading.She was the daughter of Johannes Richter.
All these people are well documented in Berks County records.Jacob Graul was a particularly prominent citizen of Reading, and he and his father-in-law, Henry Christ, both fought in the Revolution.
I got most of my information from Gail Komar, who posts periodically to this forum.She could help you learn more and possibly find other descendents of your Samuel.