I have my double cousin's wife's family tree (two brothers and sisters married each other, and one cousin was my mother, but we consider them closer than 2nd cousins). Anyway, her maiden name was Kohler, not Koehler and the names aren't the same, but you might get some clues. John William Kuhler b 1796 Prussia had five children. Two birth not specified. One born in Cologne, Germany; one in Eberfeld, Germany; and one, August, in Liechlingen ?, Germany. in 1837. In 1854 at age 17, the next youngest, August, came over ay way of Antwerp. He came to Chicago where he worked in a sash and door factory. In 1855 his parent came over. All went to Clarion, Iowa. 21 May 1860 Naturalized. In 1861 they returned to Chicago and on to Freeport, IL. August married 27 Dec 1862 and in Feb 1863 he enlisted in Company C 46th Illinois Regiment. Discharged at Baton Rouge, LA 1865 to Clayton Co., IA where he farmed before moving in 1878 to Dakota Territory where he lived in a dug-out some 3 miles east or so of Wakonda, SD. Does this give you some clues? More data available.