This is what I think I've found about Jacob Saylor and his family from the Mercer County history:
born abt. 1812 in Baron, Germany
died abt. 1870 in Mercer County, Pennsylvania
Elizabeth Shaefer - married in Germany
died 1858 (probably Mercer County) Pennsylvania
Children (5 living, 7 dead in 1909)
Jacob - dead by 1909
Fred - working at Bessemer Mills, Sharon, Pa in 1909
Elizabeth - dead by 1909
Catherine - widow of John Frohman, West Salem Township
Theresa - wife of Adam Lininger, Greenville, Pa
The above information suggests the names and ages of individuals who should be in the 1850 census. I found a family who could be my Jacob Saylor. The image and transcription are below.
______________________________________________________________________1850 U.S. Census, Pennsylvania, Mercer, Hickory Township, printed page 88, dwelling 327, family number 332, lines 29-34. 5 October, 1850. (FamilySearch.org Film #444764, Digital GS# 4205100, Image #00052)
(Click on the image to the right to see it larger.)
Jacob Sailor, 37 years, male, miner, born Germany
Elizabeth Sailor, 36 years, female, born Germany, cannot read or write
Elizabeth Sailor, 11 years, female, born Germany
Jacob Sailor, 13 years, male, born Germany
Frederic Sailor, 7 years, male, born Germany, in school during the year
Catherine Sailor, 5 years, female, born Germany
______________________________________________________________________Notes, Comments, Thoughts
Why, if 5 children were still alive in 1909, were only 3 living children mentioned in the biography in the county history? Sibling (or half-sibling) rivalry? A rift in the family? Who are the other two living children?
In searching the 1850 U.S. census in Pennsylvania for the surnames Saylor and variants, I found no others that include Jacob Saylor with a daughter, Catherine of about the correct age.
The names in this census record agree with the names in the county history. The age for Catherine Sailor in this census closely agrees with her birth date of June 5, 1844. If this is my Saylor family, the birth years of the family members are as follows: Jacob, abt. 1813; Elizabeth, abt. 1814; Elizabeth, abt. 1839; Jacob, abt. 1837; Frederic, abt. 1843; and Catherine, abt. 1845.
If I can find Jacob Saylor in the 1860 U.S. census, his wife should be Mary. The children may be the same but 10 years older. Some of them may have moved from home.
A brief google search for "Baron, Germany" did not show a location of that name. I'll have to do some historical map searches and consider alternative/similar names.