I have tons on this family. Your John was born Johann Adam Kuhlmann, 6 Nov. 1851, son of Hermann Heinrich Kuhlmann and Susanna Kreis. Herman (13 Apr. 1829-18 July 1896) was born at the village of Drehle, Hannover, German, christened at Gehrde. Came to America in 1840's, married Susanna Kreis in York Co. PA about 1846, then to IN. Their first child Samuel (our line) was born York Co. 1847. Susanna d. 1870-1880, probably buried at Whitecreek. Herman is buried at Riverview in Seymour. He m2 to Mary Muenter Mackey; they had a daughter Tillie (m. Henry Sager.) Your John married Elizabeth Mackey, TECHNICALLY his step-sister (not blood relation) because his dad married her mom. John was older, and out of the household before that marriage. He was 32 and Lizzie 20 when they married in 1884.
Hermann Heinrich Kuhlman was the son of Bernhard Henrich Kuhlman and Anna Katharina Dirckes, of Drehle, Germany, who came to America with Hermann and another son, Johann Heinrich Kuhlmann. These families were all written up in Bartholomew Co. Family Histories Book (1999) available from Barth. Co. Genealogical Society, copies at the library.