Facts and Events
From research of Frank M. Jackson: "Birth date of 24 Feb 1733 from DAR Bible Records, Vol. 209, p. 36, NYS Library. Mentioned in the will of Jane (Seaman) Jackson dated 3 March 1785."
Bunker's book pg 222 says that he died in 1779 but that does seem very doubtful now and I will remove that d/o/d. (1) This Obadiah is the only man by that name old enough to own the 1787 earmark and therefore would be still alive. (2) This Obadiah was found on the 1790 and 1800 census. (3) Note below his son lived "at Jerusalem South near where his father lived". (4) I need to check the above Jane Seaman Jackson's 1785 will to determine if he was still living or mentioned as being deceased. (5) The 1730 d/o/b conflicts with another child being born that year, so the 1733 d/o/b seems to me to be more logical.
And ALT date of birth and death is recorded page 133 of the book "Jones Family of Long Island" as b 1730, d 1802. Also states that "Obadiah was the eldest son of Justice John Jackson, son of the 2d Colonel John, who was a brother of Phebe, wife of William Jones. He m. Almy, dau. of Jacob Seaman, and lived at Jerusalem South, near the old mill where his father lived. . . .By the death of an older brother (unnamed) his son, Jacob S. Jackson, b. 1763, became the only son and heir, and SUCCEEDED TO HIS FATHER'S ESTATE."
1790 Census Obediah Jackson, South Hempstead, Queens, NY
1800 Census Obadiah Jackson, Hempstead, New York 0-0-0-0-1// 0-0-0-1-0// 0-0
Obadiah's daughter, Elizabeth, named a son Obadiah after her father.