I believe that your William Coffin, son of Libni Coffin and Hepzabah Starbuck, was actually born on October 26, 1771 in New Garden, Guilford County, North Carolina.He died on September 23, 1846 in Boonville, Dallas County, Iowa.I was on a recent genealogy trip to Iowa and have a photograph of his headstone if you are interested.Dallas County history relates that he was the first white settler to die in the county.William's headstone provides his age as 74 years, 10 months and 28 days.
William was first married to Hannah Iddings on June 8, 1797 at the Deep River Monthly Meeting in Guildford County, North Carolina and I have found no children born to this marriage.He married Mary Duncan in abt. 1800 in Montgomery County, Virginiaand 8 children were born to this union.Mary Duncan died in abt. 1826 and William married Pharaba Boswell on November 29, 1827 at the Chester Monthly Meeting in Wayne County, Indiana.You will find William and Pharaba as well as some of William's children mentioned in many of the Indiana Quaker Monthly Meeting records.
I do not think that William's last wife Pharaba followed him to Dallas County, Iowa, however, I have found her living in Oskaloosa, Iowa on 2 census records after William's death.William's son, Greenberry Coffin was with his father is Dallas County and latter settled in Mahaska County, near Oskaloosa, Iowa, where he lived the remainder of his life.
I hope that this helps you in sorting out William Coffin's wives.Please let me know if I can be of any further assistance.Also, I would be interested in knowing your connection to this William Coffin.