My connection to the Mertes Family is only through the marriage of Anna Maria Hennen (b. 1871), d/o Nicholas Hennen to John Mertes (b. 1865). Nicholas Hennen is my great-grandfather, Mathias J. Hennen's brother.They wereboth sons of the Peter J. Hennenwho wrote the letter you mentioned. I am working on a Hennen book, where I want to publish the letters, and will send you a copy then.