If this is the same John Briggs we are from the William side. For a long time my father in law thought he was related through Clement Briggs. A 4th cosin of ours is doing a rearch on William 1646 and thinks we are from John Briggs 1619. Her name is Beverly Newton and she lives in Pittsfield Maine. She doesn't have a computer. I can put you in touch with her if you would like. She has done a wonderful job and has turned the book over to the state of Maine. She has nothing on John Briggs other than b ca 1619 maybe in England died 1686 in Taunton. If you have anymore we would like to know. My husband's family settled in Livermore and Turner Maine.We live in Georgia. We were up in Maine at Christmas time to take pic of the graves and to see if we could find the old farm land. Of course other people own the property now but we might be interested in buying it just to get it back in the family and maybe moving up there when my husband retires. There doesn't seem to be very many people left from the William side.