1.  Marriage Record:

2.  1790 Census Index/Images (online at Ancestry.com):  not found.
 
.  Frederick Clifton Pierce.  1895.  The Descendants of John Whitney, Who Came from London, England, to Watertown, Massachusetts, in 1635.  Self-published, Chicago (transcribed by and online at the Whitney Research Group web site, www.whitneygen.org):

680. ISAAC WHITNEY (Jason, Mark, Benjamin, John), b. Natick, Mass., Apr 17, 1770; m. ----- -----; m. 2d Mrs. Susanna (TURNBACK) HALL, b. Pennsylvania, May 11, 1780; she m. 3d a Mr. DODGE and had one child by him. She d. at Ray, Mich., Feb 9, 1867.   He was born in Natick, Mass., emigrated to New York, and died in Middlesex in 1817. He was a kind husband and father, and true Christian man. He was a pioneer in that section when it was settled by the Indians, with whom he was on friendly terms. He was also able to converse with them in their dialect. After the death of his first wife he married a widow, Mrs. HALL, for his second wife, and she had five children by her first husband and one by her third. Isaac was an extensive farmer and one of the largest in that part of New York. He d. in 1817; res. Middle- sex, Ontario Co., NY.     1706. i.     JASON, b. -----; m. and went to Texas.     1707. ii.    ROBERT, b. -----; d. -----.     1708. iii.   ELIZABETH, b. -----; m. ----- OSGOOD, and moved to Michigan,                   where they had a large family, and died.     1709. iv.    SAMUEL, b. July 9, 1811; m. Ann STROUP.     1710. v.     JOHN FISHER, b. Oct 25, 1809; m. Phebe NELSON.     1711. vi.    ISAAC, b. Nov 12, 1817; m. Sarah STROUP and Mahala STROUP.     1712. vii.   JESSE, b. May 3, 1808; m. Eliza C. SHEPARD.     1713. viii.  JAMES, b. in Middlesex, NY; m. and d. there s.p. in 1847.