Hopa, memoirs of a German immigrant to America

I have not read the book, but I know who it is about. William Otto Mohrmann was born 23 May 1835 in Holzendorf, Mecklenburg, Germany, came to America in the 1850s, with his family. They lived in what is now part of Chicago for many years. William was an officer in the Civil war, and was promoted from corporal eventually to captain. Some time after 1890 William moved to Central Lake, Michigan, where he was a farmer. He died there in 1912. The editor is his great grandson