The 'Hugo Rahn' that you asked about was born in Kirchhayn, Wisconsin, on December 14, 1877. He was the son of Julius Friedrich Christian Rahn and Ernestine Rosalie Wilhelmine Krause. Julius was born in 1832. His parents were Karl Heinrich Rahn (b. August 27, 1779) and Hanna Louise Steingraeber. They arrived in New York on Sept 16, 1843, on the brig 'Dorothea'.
Hugo had two children that we know of born in Manitowoc. A daughter, Lorena Mathilda Louise, who lived only 2 days, and Hugo Rahn (jr.) who died in 1939.
We are the authors of 'The Rahn Family of Wisconsin', copies of which can be found in various Wisconsin libraries. If you wish to correspond, please email me at Russell.Rahn1@Verizon,net.