My great-grandmother, Anna Mertes Helf, (1867-1960) had a sister, Gertrude Mertes, who married a Joseph Wershem in 1888. Gertrude & Joseph Wershem lived in Kaukauna, WI. Anna, Gertrude and their brother Joseph Mertes were the children of Johann Peter Mertes & Mary Josephine Konz.
Here’s an obituary for my great-grandmother, Anna Mertes Helf (1867-1960)written by her son, my grandfather, Lewis Helf.
"Article in Kaukauna paper – 1960 - Mrs. J.P. Helf, 93, Dies in Her Milwaukee Home"
"Lewis Helf, 735 S. 22nd St, Milwaukee, wrote the following Letter to the Times about the recent death of his mother:
"Thought you would be interested in the passing away of a pioneer ofKaukauna—my mother Mrs. John Peter Helf (nee Mertes), aged 93, who died On Feb. 13 in her home in Milwaukee."
"Nine children survive, including this writer. Eight were born in Kaukauna,in the order named: Louis, Edward, Anthony, Olive, Anna, Lillian, Helen, Gertrude and George.The last named, George, who is now a resident of New York City, was not born in Kaukauna. Old-timers will remember my mother as the wife of the late J.P. Helf, (died 1936) who operated the Helf Brewing company on the north side, which was established about 1886. The family left Kaukauna in 1906, when the brewery and malt house was sold to John Regenfuss."
"The late Mrs. Joseph Werschem was her sister, and the late Joseph Mertes, Of Kaukauna, was her brother. Many of her nephews and nieces still reside in Kaukauna."
Could Gertrude Mertes' husband Joseph Wershem be your great-grandfather? If he was born in 1859, he would have been 29 when he married Gertrude Mertes.