According to his gravestone, William died at age 92. He was a graduate of Harvard College, class of 1747, and was among the signers of the Declaration of Independance.
The inscription on his gravestone reads as follows:
"In memory of William Ellery born December 22 1727, graduated Harvard College 1747, early in the contest between Great Britain and her American Colonies, he left the practice of Law to represent this State in Congress. He was an active and influential member of that body for many years and one of the signers of the Declaration of Independence. He died after an illness of four days February 15 1820. He was in full possession of his powers to the close of his long life, rarely unfitted by disease for study, society, or official duties and waiting for death with the hope of a Christian."
Information on William's life and his gravesite can be found at findagrave.com.