I'm pretty sure the Mills material that the Orange Co. Genealogical Society has was collected by William Heidgard (am not sure of the spelling of his name). It's probably similar to what is in the New Paltz library, where I spent an afternoon about ten years ago going through a very confused file. So I just thought I'd warn you to be very careful and check whatever sources he may mention. He collected an enormous amount of information, but what I saw was repetitive and disorganized. Helen Ullmann