In case this helps anyone looking for Eilerts
in the US, my Father-in-Law's family name was
changed from "Eihlert" to "Ahlert" after the
name came to the US.
Family oral history has it that the original
spelling was "Eihlert".
This family was/is in Indiana since at least
1950, but probably before that.
I will update this board if I find out more,
as I am just beginning my search on this branch.