"Obadiah became a freeman at Coventry on 3 May 1743. He was a deputy to the General Assembly from Coventry in 1764 and 1768 . . . Obadiah appears as the head of a family at Coventry in the censuses of 1774, 1782, and 1790."
(Source for the above information: Linda L. Mathews in "A Line of Descent from Elkanah Johnson of Coventry . . ." in RI Roots Magazine, Vol. 29, No. 3, p. 121)
Obadiah's will dated 13 Feb 1791 at Coventry mentions wife Sarah; sons Isaiah, Hosea, John dec'd, & Joshua; dtrs Mary (Matteson), Katherine (Walker), & Welthan; grandson Freeborn and granddtr Amey, children of dec'd son John Johnson.