Thank you for your post. It confirms my suspicions.
I've only recently started searching for the descendants of Ludwig and Lewis. My direct line is through their brother Malachi.
Didn't John and Mary also have a son Henry? There was aHenry, age 22, enumerated with them in the 1850 census.
I'm curious as to whether or not the other child may be a Peter Isley. He married Mary Couton on23 August 1836. A Lewis Isley was the bondsman. Peter and Mary first went to Ray County, Missouri and their first child was born there in 1838. They eventually went to Gage County, Nebraska.
I'm afraid that I do not know where any of this family is buried.