I agree with you, that Joseph and Jacob were related.They both appear in the 1850 Madison Twp census for Armstrong Co.Most importantly, the census listed them next door to each other.Joseph and his family did move to Allegheny Co. before the 1860 census, and he became a coal miner.
1850:Madison, Armstrong, PA
Jacob Petegrews 49
Elizabeth Petegrews 54
John Petegrews 21
Lucinda Petegrews 16
Sina Petegrews 19(Josinah)
1850 Madison, Armstrong, PA
Joseph Petegrew, farmer, 30; Rachel 25, Aaron 6, Ann M. 4, Oliver2, Hannah 0.
(This household next door to Jacob Petegrews)
1860 Penn, Allegheny, PA
Joseph Petigrew, miner, 39; Rachel 34, Aaron 18, Anna 16, Oliver 13, Hannah 12, John 8, Robert 5, Elizabeth 3.
1870 Penn, Allegheny, PA
Joseph Pettigrew, coal miner, 51; Rachel 43, Robert 16, Hannah 20, Elizabeth 12, William 4, Ellen 2, Albert 4 mos.
1880Verona, Allegheny, PA
Joseph Pedigrew, farmer, 65, self/fa/mo b. PA/Sct/Sct; Rachel 55, Robert 24, Elisabeth 22, Wm. Thos. 14.
This last census entry is the most confusing.Joseph's parents are given as b. in Scotland??If Joseph was son of Robert then his father was b. PA.Note that Joseph had a son Robert and a daughter Hannah, his parents' names?From the 1850-80 census records, Joseph was b. variously 1815-1821.Robert did have two sons in the 1840 census b. anywhere from 1810-1825.
Previously you mentioned: "The name Pettigrew appears in West Newton Cemetery [Rostraver Twp., Westmoreland Co.]Thomas 1839-1874, father, David A. 1843-1932, Elizabeth 1853-1911, James H. 1878-1947 and Anna Peters 1877-1941."
These were latecomers to America, so don't see a connection to other Westmoreland Co. Pettigrews.This David was b. in Scotland about 1845.
Home in 1880: West Newton, Westmoreland, Pennsylvania
Estimated birth year: abt 1845
Father's birthplace: Scotland
Mother's birthplace: Scotland
David Pedigrew 35
Lizzie Pedigrew 26, wife
James H. Pedigrew 1
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