This branch of the Family can be traced back to Peter Iseli (1784-1848), the son of Hans Iseli and Christina Locher. Peter married Verena Kunz of L?tzelfl?h in 1803 and had three children, Christian, Johannes, and Katherine. Christian (1806-?) immigrated to America in 1833 and settled in Switzer Township, Monroe County, Ohio.

Christian and his son Jacob lived on Steiger Ridge Road, also known as Township Road 218 where they maintained a sizable farm. The most notable member of the Isaly branch is William Eugene Isaly (1862-1923), the grandson of Christian and founder of the Isaly Dairy Companies of Ohio, best known for the "Klondike" ice cream bar and the "skyscraper" ice cream cone. The family sold the business in 1970 and it is now part of the Anglo/Dutch Unilever Group. In 1995, seventy descendants of the William Eugene Isaly gathered in Columbus for a family reunion. The genealogy for the descendants of William Eugene Isaly has been completed through 1983.