A Theory on who Samuel Harman is.
As you suggested I looked in York County. I found no Harmans in the late 1840s in Fawn Township. Since the 3 children of Samuel in the 1850 census were listed as being born in Pennsylvania I decided to look elsewhere in York. Then I looked at the 1840 census for York County and found 9 townships with Harmans. Then I looked to see where the Kuntz(Koons,etc) were in 1840. One township that had both surnames was Windsor. I looked in the Windsor tax records and there was Samuel in 1845 along with Peter and George. Also there was Ludwig Kuntz. A few years later John Harman shows up in the taxes.
I found that Peter and his wife Frederica were from Germany. I thought that Ludwig Kuntz would be also since Ludwig often is Anglicized to Lewis. What could be more natural than the children of 2 families from Germany to marry. Peter Herrman ( Herman, Harman) who died 7 July 1852 has a York County will U-15 which lists his children. There are John, Mariah, Elizabeth who marred Philip Shade, Magdalena married Jacob Smeltzer (in Chanceford in 1850), Susanna married Jacob Jones, Frederick, Samuel, William Otterbein, and Rose Ann Margareta.
Peter is called Rev. He also in his will asks that his wife be left some of the medicines he has to continue his practice. Another interesting item from the will was that Mariah was to get one dollar and that was all.
In the 1900 census Samuel’s son Amos says he was born January 1846. Amos died 11/10/1920 and is buried in Center Presbyterian Cemetery. He was age 75-9-24. Samuel’s son Washington is George Washington Harman born 1847 died 1918 buried in Centre Presbyterian Cemetery in Fawn Township. This area of York County is very close to the Maryland line.
Peter married Frederica Bramer Miller in 1837 in Salem Co. NJ making Samuel's mother Peter's first wife Anna Barbara Eichart born in Switzerland,
how do you know that Samuel born 1824 who is in the 1850 census is the Samuel who died in 1864 in Chester Co.or for that matter ever lived in York County?