William has also been reported as born in 1718. It depends on whether the statement "in his 45th year" means he had already turned 45, or was now entering his 45th year of life.

DISCREPENCY: The 1893 Tanner genealogy book by Elias Tanner indicates on page 1 that William was born about 1729, then on page 87 he indicates between 1725-1730. Those dates clearly don't make sense if he was about 45 when he died in 1763 as indicated on his marker. But if the age given on his marker is correct, William would have been born about 10 years before his parents were married, if they married 1728-1730 as indicated by Elias. One of these dates appears wrong

William married Hannah Newcomb Mar. 23, 1749. They had six children:
Consider b March (or June per Elias) 1750;

Tryal b. Dec. 20, 1751;

Ephraim b. June 17, 1753 or 1754 (June 4, 1754 per Elias);

Dea. Ebenezer b. Jan. 20, 1756 (or 1757 per Elias);

William b. Jan. 28, 1762;

Joseph b. 1759 (or June 1763 per Elias)

After William's death Hannah married Elisha Hatch

It's difficult keeping the William Tanner's all straight. In Elias' book (page 87) he discusses the William Tanner of this memorial, and indicates that he was born in Rode Island, moved with his parents Thomas and Martha from Rhode Island to Cornwall in 1740, and married Hannah Newcomb of Kent on March 23, 1749. William and Hannah had 6 children all born in Cornwall, one being a son named William (b. 1762), who in turn also had a son named William (b. 1789). A few pages later (page 95) Elias discusses early families who settled in Cornwall, including Thomas and William Tanner from Rhode Island with their families. (Thomas might be the father of this William). In the next paragraph he mentions a William Tanner Jr. called the "Great Tanner" because of his size and to distinguish him from others of the same name. He then continues and discusses a William Tanner Sr. from Rhode Island; this sounds like Elias might be referring to the William who was one of the early families, in which case the "Great Tanner" might be his son. But there were other William Tanner's including a son of Thomas, so it isn't completely clear which William was "great".

Adding to the confusion, in "Historical Records of the Town of Cornwall", Theodore Gold (page 189) refers to William Tanner who settled in the Hollow, and states that his father of the same name was from Rhode Island. Gold indicates that the younger William is the "Great Tanner". Then on page 246, he refers to the "Great Tanner" as being a native of Rhode Island. These passages are confusing. Reading the paragraph on page 246, one would think that the original William from Rhode Island is the "Great Tanner", but that doesn't match what was indicated earlier, or what was indicated by Elias Tanner. Confusing.