Mertz Genealogy
Mærtz Hierarchical Project &
Our Ancestors and their Families
Mærtz Hierarchical Project
Hangviller view
The Mærtz Hierarchical Project, when 100% complete, will list every male Mertz or Martz (thus Mærtz) who -- a.) was a direct descendant of any of what I call the “eight original American ancestors”, b.) was born before 1850 and c.) was listed as head of household in his own right by no later than 1880 (meaning typically that he survived to adulthood, married and had children).
Each qualifying male identified is assigned a designation code which links him back to his original or immigrant ancestor. He is also identified in every Census (1790-1880) in which he was named (regardless of the spelling). And I have made note of whether he can be found on find-a-grave.
The designation code is key. Each original Mærtz ancestor is given a unique single-letter designation code, for example my ancestor Peter Mertz is designated P. The second generation is numbered sequentially in birth order, I descend from P4. Lower-case letters and numbers then alternate. So a designation code of H5d1b3 would indicate the third son (3) of the second son (b) of the first son (1) of the fourth son (d) of the fifth son (5) of the immigrant H.
In part, this is a geographic dispersion project. An immigrant came to America in the 1700’s and settled somewhere in Colonial America, some of the next generation spread out from there maybe to the next county, the next generation maybe to a neighboring state and so on. So I have tracked all (surviving) designated males to 1880 when people of this name lived in 15 different states and 200 different places (townships) in those states.
Eight Original Ancestors
As of now, I have identified eight original American Mærtz ancestors and here is their single-letter designation code and a very brief biography:
H -- John Henry (Johann Heinrich) Mertz came to America in 1737, settled in Rockland Township, Berks County, PA and was the founder of Mertz Church there. He has many, many descendants alive today.
Y -- Jost (Johann Jost) Mertz came to America in 1747, found his way quickly after his arrival to Mertz Church and settled near there. After a lot of work we now know that Jost was actually John Henry's younger brother.
J -- Johannes Mertz, probably the man of that name who arrived America in 1749, also found his way soon after his arrival to Mertz Church.  I think I know enough of the German family of John Henry and Jost to rule out that Johannes was another brother, but the fact that he came to Mertz Church leaves open the idea he may been more distantly related, perhaps a cousin. Until a known descendant of Johannes participates in the Mertz/Martz DNA Project, we probably won’t have a clearer idea on whether he was related to the other two or not.
Those three, associated with Mertz Church, practiced the Lutheran faith.
John David Mertz, proven by the DNA project as not related to the the Mertz Church Mertzes, came to America in 1733 and settled in Longswamp Township, Berks County. His two teenage sons accompanied him on the trip and the three were early elders at the Longswamp Reformed Church. So, besides their DNA, the fact that the Longswamp Mertzes were Reformed and the Rockland Mertzes Lutheran also helps to distinguish these several Berks County families and demonstrate they were not from the same family back in Europe.
Since the coding structure becomes a little cumbersome after 3, 4 or 5 generations, I decided to give each of John David’s two sons their own unique single letter code.
N -- Nicholas was 18 when he arrived with others in his family in 1733. I sometimes call him a teenage immigrant.
P -- Hans Peter.  Peter was 15 when he arrived America in 1733 with his family. He was another teenage immigrant. (Peter is my 5G-grandfather).
The above five all came first to Berks County and, excluding Johannes, we actually know their European ancestors for one or two generations back into the 1600’s.  The names of all were spelled Mertz (or Merz) in Europe and in Berks County. Descendants of the ancestors of these immigrants living in Germany and Alsace today spell the name Mertz and many American descendants of those immigrants also continue to spell the name Mertz.
But as people moved to a new place in the 1700’s and into the 1800’s in many cases their name came to be spelled Martz (sometimes Marts) in the new place. Many people named Martz today descend from one of the above five Mertz immigrants.
Now we meet two more original ancestors.
T -- Theobald Martz who appeared in and settled in Frederick County, MD in the latter half of the 1700’s.
S -- Sebastian Martz who appeared in and settled in Rockingham County, VA by 1790 or so.  Sebastian especially had a huge family and many ended up in Ohio and beyond.
Some people say Sebastian and Theobald were brothers, that they were sons of Balthazar.  I think we now have sufficient DNA evidence to rule out that they were brothers and I don't have any idea the name of either one's father, I doubt very much it was Balthazar.
But note that Peter and Nicholas were brothers as were John Henry and Jost. So the use of a unique single-letter designation code is just a ystem.
Having a unique single-letter code should not be construed as an indication that any person so designated was not related to another. Nor does it necessarily mean the person was an immigrant. It’s possible that one or the other or both Sebastian and Theobald was born in America. Thus I have crafted the original ancestor terminology rather than immigrant ancestor.
Now for Sebastian especially and Theobald somewhat, the earliest spelling was most often March (sometimes even Marche, almost a French name).  But all of their descendants eventually and pretty quickly became Martz. Interestingly, there are a few descendants of theirs who by the mid-to-late 1800’s had evolved to the Mertz spelling.
There is one more original ancestor to meet.
G -- There was a George Mertz who appeared early in Heidelberg Township, Northampton County (the part that later became Lehigh County). I am quite sure he was the immigrant of that name who came to America in 1732. His only son, I believe, was named Philip.
Philip was named as a contributor to the (2nd) building of the Heidelberg Church in 1756. The church served both the Lutheran and Reformed faiths and I do not yet know which Philip was. He was named on the 1781 tax list of Heidelberg Township.
After that, in the same place, in church records and/or Census, we find men named Dewalt Mertz, William Mertz, George Mertz, Joseph Mertz and a younger Philip Mertz. And I believe several of this line ended up in Carbon County, PA and from there, some of the Carbon County Mertzes migrated to Westmoreland County, PA where their name came to be spelled Martz.
The G line, George and his descendants, has been the most difficult line for me to document. Especially the earliest members of this line were only named in American records once or twice. I do not claim to have sorted them all out. But I feel quite confident in my conclusion that the Heidelberg Mertzes, the Carbon County Mertzes and the Westmoreland Martzes are all descendants of the 1732 immigrant George (G).
I also believe I know enough about all of the Berks County Mertz lines to rule out that George was related to any of those Berks County immigrants. DNA confirms that and in what is an interesting nuance, seems to hint that George may have been related in some way to Theobald. (We are working hard to confirm if this is the case.)
Why Does This Project Exist, How Does It Work?
The reason there is a Mærtz Hierarchical Project is because so much of what has been published about persons of this name is wrong. Many errors have been made, more than I have seen for any other family I have ever researched. The reason for the many errors is that names were repeated. In just the first 2 or 3 generations descended from the original ancestors, there are more than a dozen persons named Jacob Mærtz, John Mærtz and Henry Mærtz. There are almost as many Conrad Mærtz, Philip Mærtz, David Mærtz, Abraham Mærtz, Peter Mærtz and Solomon Mærtz. Too often a person researching one particular ancestor with one of these oft-repeated names has found something out about someone else with the same name and mistakenly connected dots that never should have been connected.
So the idea is that if you are tracing your ancestry and you find the Mærtz name in your family tree, you should come to this website first. Especially if you can identify your Mærtz male ancestor in the 1880 or earlier Census, you should be able to find him here and find everything I know about him.
You will find out not just who he was but what documented facts there are substantiating my conclusions.
There are a variety of separate resources here to help you find your guy -- remember there may be a dozen or more of the same name, you have to start by finding the right one.
Start With the Census Listings
This is probably the best starting point. So just by way of example, I’ll use my own ancestor to illustrate. I know my 2G-grandfather was listed as George F Martz in the 1850 Census and he was age 28 and lived in Point Township, Northumberland County, PA. (All Census references are to the way people are currently indexed by
Now his name really was George Peter, or George P not George F, and this is about the only instance where his name was mistakenly spelled Martz -- nonetheless, I would start with how listed him.
The Census Database is a list of Mærtz head of household names in every Census 1790 through 1880. Once in any particular database, the records there can be sorted by clicking on any column heading. So I would click on the 1850 Census year to enter that database and then click on the column headed Census Name/Age to sort the names and then I could quickly find all the George Mærtz and within that group easily spot George F age 28 in Point Township. Or I could instead sort the list by Census Place and find all PA, Northumberland, Point in that list and could then quickly within that group find George F Martz age 28.
Either way I chose, what I would be looking for is his designation code. And so I would see that George Peter was designated P4a4. He’s my guy.
By the way, if I knew a person should be in some particular Census, I went to great pains to find them and I list in the Census listings everyone, no matter how badly corrupted their names. Many people of this name are incorrectly listed as Marty in Census and many other mistaken transcriptions also appear. I have made every effort to find them but you need to remember, in the Census lists, they appear under their name as listed it, no matter how badly corrupted.
Census Database
Original Ancestors and Their Descendants Books
So, continuing wth my example, I now would know I need to go find P4a4 in the “P” (Peter Mertz) original ancestor book. The simplest thing to do is actually click on the designation code in the Census sheet and the P book will automatically open. But if you want to come back later or if you want to browse a different book, you can find each book under the button below.
Original Ancestor Books
Please Note
As noted above, many mistakes have been made over the years by genealogists attempting to identify people of this name. Most often, the mistake was made because multiple men of about the same age in about the same place may have had the same given name. You might only want to know about your ancestor named, for example, Heinrich, but to get things right, I am interested in all of them. Elsewhere on this website is a white paper titled "Eighteenth Century Pennsylvania Mertz and Martz" and I list there and briefly profile every Mærtz male born before 1800 organized by given name -- so you can see all the persons of each given name and see what factors I used to distinguish among them.
I also discuss in that white paper the biggest mistakes that have previously been made by others who mixed people up. I critique many well known, but in my opinion, erroneous other sources. I have fairly carefully reviewed, over the years, every publication I could find that purports to cover any of the various Mærtz lines. Genealogy is too often, in my opinion, a cut and paste activity. So once a mistake was made, it got picked up and propagated.
Right now, there are over 600 different family trees posted on that identify a man named Heinrich David Mertz. His is a made-up composite name originated by a guy who thought that a man named Heinrich moved and at the same time changed his name to David. It is laughable, but that’s what he thought and so he made up the name Heinrich David and merged two different lives into one.
So I felt it necessary to identify these other sources and discuss them and their approach and how they went wrong.
Final Disclaimer
So this is a work in progress.  Despite all my criticism of others, I do not claim that everything I set forth here is right. There could well be mistakes, I’m sure there are.  But it is the culmination of years of research into all things Mærtz.
I am always wiling to discuss anything further with anyone interested. I am especially interested if you know something perhaps I don’t know -- if you have found some documented evidence of something that I may never have seen. By all means, let me know. Let’s discuss it. I am quite open-minded and my objective is to get things right.