Greg, I'm sure it would be useful to go back to those threads I put in my previous message, and extract the sourced information. I think Brian Lawson gave you some census records?
Karen's tree which she posted gave names and years, but didn't give places or any supporting information. Not even which families were in the US, and which were in Maughold. When did your first US ancestor Robert leave the IOM? What ship? Who travelled with him? His age given on the passenger list?
Could you write down what information was given about him in US censuses, at marriage, at burial? Was his place and date of birth given at burial and/or in a census?
If you are certain of his bapt or birth date from one or more of these sources, who were his parents? What date and where did they marry?
Do you have the IOM census records for them?
It is through going back step by step that you will see where the gaps are, and people will help you fill them. Could you write down each generation with these details included? - Starting with the US Robert Corkill who was bapt in the IOM, and going back from him?