You are correct. I am a descendent of both Gesina Kahrs and John Henry Kahrs. Gesina married Jacob Esch. Their daughter Mary Esch married Samuel Weiss. Their Daughter Eunice Weiss married Edward Kahrs. Their daughter Majean Kahrs married Caleb Sparks. I am Majean and Caleb's daughter, Amy.
My Grandfather, Edward Kahrs is the son of John Henry Kahrs (grandson of Claus Kahrs and Catherina Hagenah). My grandparents were cousins to each other, making me related to Catherina Hagenah by two of her children.
You are correct on Michigan. My family is from Leelanau County (specifically--Leland), Michigan.
I have just recently become interested in genealogy. Do you know information further back than Jurgen Hagenah and Benjamin Bruckner and Hedeweg Hartman?
p.s. What is your relationship to Johann Hagenah?