William Stahl's obituary says he was born in Pottsville in about 1841 but his 1864 enlistment record for the Civil War says that he was born in Philadelphia in about 1836. According to the 1850 Danville, PA Census he was born in about 1837 - and according to the 1860 Danville, PA Census he was born in about 1835.
Based on currently, available information it looks like William was born in Pennsylvania and was living in Danville, PA until the early 1860s when he moved to Pottsville where he was working as a puddler in a steel mill. While living in Pottsville in 1864 he enlisted in the Army for the Civil War. He returned to Pottsville after the Civil War and he and his family are in the 1870 and 1880 Census for Pottsville. By 1890 he was living in Reading, PA.
His obituary says the he is survived by a sister Mrs. Sarah Lightheiser - this should be Mrs. Sarah Werkheiser.
Comments - February, 2021
Grand Army of the Republic Membership Records - February 19, 1864
Reading Times (Reading, PA) - December 24, 1912