We know Major George Mertz from his father’s will. He was a Major in the War of 1812. He is designated H5a.

Extensive write-ups on George S Martz, grandson of Major George Martz, and John H Martz, great-grandson, are given in the History of Frederick County, Maryland, by Williams and McKinsey published in 1910. Both write-ups attempt to recount how the Martz family came to Frederick County, though, in the write-up on George S, it says his grandfather, Major George, was the early settler of that name while in write-up on John H, it adds another generation and says that George D Martz, father of Major George was the early settler.

Typical of all county histories written around the turn of the last century, I believe they are reasonably accurate on the biographies of living people and the further they delve into the past, the more inaccurate they become. Case in point: About the father of Major George Martz in the write-up on John H, this county history says: “George D Martz was born in Wurttemberg, Germany. When he reached adult age, he and two brothers left Germany where they landed at Philadelphia. He settled near Lancaster and afterward removed to a place near Westminster, in what is now Carroll County, where he was engaged in milling for a short time. Mr. Mertz next removed to the Middletown Valley where he purchased a mill and farm. After cultivating this land for a few years, he bought a farm of 125 acres situate a little northwest of Frederick. George D Mertz married and had four children, the oldest of whom was Major George Martz.”

I think this biography is wrong on some key points.

1. I have no idea why they call him George D. In Frederick County records, he was only ever George, and I believe he was, in fact, John George.
2. It was John George’s father, John Henry Mertz, who was born in Germany. Indeed, his brother, Jost, did also come to America — though they did not travel together. And there was a third brother George who also may have come to America.
3. I know very little about the third immigrant brother, George. I have speculated that maybe he was the George Martz reported in Lancaster County in the 1790 Census but I don’t know that for sure. I do know that George, the possible immigrant, was born in Germany in 1708 ruling out that he was the George who died in 1822 in Frederick County with a known son George.
4. Whether that immigrant George moved into Maryland at some point and may have had something to do with how John George, his nephew, found his way to Frederick, I can’t say — but there is no evidence that things happened that way. So I basically leave George, the possible immigrant, out of the story I tell.
5. I believe the more straightforward story is that John George and his brother William, sometime after the Revolutionary War, left Berks County for points west, William settled in Somerset County, PA, John George in Frederick.
6. Whether those other references to George being first in Carroll County and then the Middletown Valley are even true, or if so, whether they pertain to this George or some other George, I have no idea.

Now, remember, everything above pertains to the biography of the father of Major George as given in the write-up on John H Martz. A contradictory biography on Major George was given in the write-up on George S. It says: “Major George Martz, an officer in the United States Army in the war of 1812, the grandfather of Lewis J Martz, came to America from Germany when he was quite a young man. He was accompanied by his brother who settled in Pennsylvania. George Martz made his home in Frederick County, MD; he was married to Catherine Reese and among their children was a son named David S.”

I think this biography too is wrong, if only because it is totally contradicted by the write-up on John H Martz.

1. I think Major George Martz was born in Frederick County. His 1786 birth date is known from his tombstone. His baptism went unrecorded but his sister Rosina was born in Frederick in 1781 and his sister Christina in 1784.
2. I think it was Major George’s grandfather who emigrated to America but his father, I believe, may well have been accompanied by his brother when they left Berks County for points west.

George lived his life, I believe, in Frederick County.

Major George Martz is on find-a-grave.

In the write-up on John H Martz, the children of Major George Martz are named including daughters: Mary Ann wife of George Zimmerman, Rebecca wife of George Messell, Elizabeth wife of Joseph Angleberger and Catherine wife of Henry Gall.

In the write-up on John H Martz, the children of Major George Martz are named including sons:

H5a1 David S born 1815
H5a2 Daniel (manufacturer of coaches in Gettysburg)
H5a3 Rev. George J (many years a missionary to India and prominent minster of the Lutheran Church in Lebanon, PA) born 1822

She is said to be the daughter of John Reese, a prominent farmer and miller of northwest Frederick County.