OK, I'm a little confused so let me see if I can help you sort this out.
A William Harris married "Margaret", maiden name unknown. Do you have a date, even approximate, of when that occurred? Did Harris live in Ozaukee cty. at any point in time? If so, when and where (approximate location would help).
Do you have death dates for any of these people?
What marriage certificates have you checked? WI, IL, ? I can check Ozaukee cty. marriage records but I need to what resources you have looked into.
Let's start with that and see where we can take this. -- Carol