Jacob first married Mary Catharine Aurand, daughter of George Aurand, about 1810.

The will of George Aurand of Middleburg written in 1849 proved in 1850 mentioned daughter Catherine, deceased wife of Jacob Mertz.

I know Jacob from his 30 Mar 1782 baptism at Longswamp Reformed Church. No birth date was given in the record but it was clear that 30 Mar was the baptism date, so Jacob was born, typically, a few months earlier.

Jacob was named by his brother Isaac as a son of Nicholas in his petition to have Nicholas’ land partitioned. The court felt it could not be partitioned so should be sold and Jacob stepped up and bought it.

Jacob is designated P5c.

THE LEWISBURG MERTZES. I first began to put the life history of this Jacob together after Valerie Mertz (the wife of a descendant of his, though we didn't know that at the time) brought to my attention that a Jacob Mertz was buried in Lewisburg Cemetery, with a very large and impressive monument and apparently with quite a number of descendants also buried nearby him in Lewisburg. From his tombstone we learned he was born 4 Dec 1781.

From Census, we learned that he first appeared in the Lewisburg area by 1820 and was most likely the same Jacob Mertz who lived in Freeburg in 1810. The conclusion we reached was that he was the same Jacob Mertz baptized (with no birth date stated) by Nicholas and Catharina 30 Mar 1782 at Longswamp Reformed. Jacob bought his Buffalo Township farm from Daniel Nyhart 4 May 1822, per the history of Union County as told in the History of the Susquehanna and Juniata Valleys.

A genealogy friend of mine is Richard Aurand Sherer and based on his Aurand files, he told me that Jacob's wife was Mary Catharine Aurand. Since Richard’s Aurands were from East Buffalo Township, I couldn't immediately figure out how Jacob of Middleburg came to marry Catharine of East Buffalo, but it turns out that Catharine's father George died in Middleburg. In the 1810 Census in Swineford's -- basically just one page of households -- there was George Aurand, Nicholas' widow Catharine and oldest son Isaac.

This also provided additional evidence that Jacob was indeed the son of Nicholas. Each piece of evidence strengthened the other.

There were other Jacob Mertzes around, of course, but the others tended to stay in (what is still) Northumberland County or moved further away, so this one was generally apart from them and doesn't get confused with them.

Jacob was first listed in 1810 in Freeburg and then in 1820-1850 in Buffalo or East Buffalo Township, Union County. In 1850, he lived with Elizabeth, age 54, apparently his wife. This was confusing at first because I knew his wife as Catherine. Then I found record that the wife of Nathan Sterner (died 1829) was named Elizabeth Mertz and a death notice in Annals of Buffalo Valley gave the same death date for Mrs. Elizabeth Mertz. The explanation: Jacob married second Elizabeth, widow of Nathan Sterner. The marriage was dated 7 Sep 1843.

Jacob wrote his will the 21st day of April 1855. He bequeathed $525 and certain personal property to his wife Elizabeth who he married 7 Sept 1843. He bequeathed $20 each to unmarried daughters Barbara, Mary and Sarah so they can buy a bed and bedding, assuming they are still unmarried at the time of his death.

He mentioned his deceased son Jacob and stated he had already paid him considerably in his lifetime so his heirs were to have no further claim on the estate.

He divided the remainder of his estate into ten shares for his ten children: daughters Elizabeth (deceased, w/o David Smith), Rebecca (w/o Jacob Vandergriff), Catherine (w/o Peter Aurand), Susan, Barbara, Mary and Sarah; and sons John A, Henry and Peter.

Jacob and his wife are on find-a-grave.