J L Floyd says this about Jacob. "Jacob Martz, son of Jacob, was born in 1815 in Upper Paxton Township and died in that locality in 1882. Buried at Killinger's, also known as David's Church. He was a butcher. His first wife, Rachel Welker, daughter of John, died in 1860, at age 51. She was the mother of nine children: Uriah married Hannah Miller, Jacob died young, John W, Hannah married Adam Naubringer and second Elias Witmer, Sarah married Henry Kissinger, Elizabeth and Amanda died unmarried and three weeks apart of typhoid fever, Mary married Jerry Hoy and Jeremiah married Miss Hoffman. Jacob married second Sarah Weaver widow of Peter Schreffler and had Emma and a child that died in infancy."

This line is covered in the Meiser/Martz work and by Allen David Tallman as well and certain details I show about them comes from those sources.

Jacob Jr. is designated U1a.

Jacob is on find-a-grave, linked to his father. His memorial was put there by Kati McSweeney. Kati is terribly confused by all the Jacobs of Berks County and it shows.

She also placed a memorial for Jacob Mertz at Mertz Church and she calls him Jacob Mertz I. She had a biography for Jacob I in which she totally mixed up the three different older Jacobs of Berks County — merged them together in fact as one man. So she must believe that Jacob (U1) of Dauphin County was Jacob II (but couldn’t designate him that since she didn’t place that memorial). She has, though, designated this man Jacob III. This is all poppycock.

Jacob and Rachel had many children. One was John W who married Mary Ann Witmer. Their son Jacob A married Emma A Schaffer. Their son William A married Annie Stella Witmer. Their daughter Elda I married Nelson E Wiest and they were the parents of Roger V and William Harvey Wiest.