Miller Brickwall Shattered

I was stumped. How in the world could I possibly find information about my Miller line? Here is everything I knew about them, taken from Sister Catherine Seemann's book "The Bixenman Family and Allied Families - Volume 1" - Page 285:

 The Millers original name was Mueller with two dots over the u, as they were Germans from Germany. Mary Ann Seemann McNamara gave the picture of the Mueller family, with the brothers and sisters of Charles, for inclusion in this book. Cecelia Baldwin also sent one so several families must have it. Anna Miller Seemann named the group but did not remember the name of one brother. They are listed here as they were on the back of the picture:

-Gottlieb (William) Mueller;
-Annie Mueller; married a Quinzer;
-unknown brother;
-Sophie Mueller; born around 1868; married a Schmalzl;
-Karl (Charles E.) Mueller (Miller); born October 7, 1852 in Germany; emmigrated in 1874; in 1889 married Philomena Bixenman (born April 27, 1870; died 1939); died October 31, 1923;
-Rika Mueller; married a Susenberger;

I Say Miller, You Say Muller

I'm hot on the trail of relatives on my Miller line. Charles Miller, aka Karl Müller was my great-grandfather. Sister Catherine Seaman's Bixenman family history book lists his siblings as brother Gottlieb, who was partner with a man named George Quenzer in a clothes cleaning and dying business in New York City, Annie, who married a man named Frederick Quenzer, who was involved in a clothes cleaning and dying business in New York City, Sophia, who married a man named Joseph Schmalzl, who owned a clothes cleaning business in New York City and Rika (possibly Fredrika), who married a man whose last name was Susenberger. The name of one of the brothers is unknown. There were a few Quenzer brothers involved in clothes cleaning businesses in New York at the time.

Most Recent Genealogical Brick Walls

Here are my most likely connections to unknown DNA matches. Any matches to my other branches are probably already known since those family trees are documented quite a ways back.

Charles E. Miller aka Karl E. Müller, born 7 Oct 1852, somewhere in Germany. Came through New York around 1874. Spent some time in New York City before moving to Linn County, then Chariton County, Missouri. Married Philomena Bixenman in 1891 in Wien, Chariton County, Missouri. Moved to Fort Madison, Lee County, Iowa and spent the rest of his life there.