Posted this in his wikitree profile about a possible first wife (and children):
Since he was 41 years old when he married Mary Howland, it is perhaps possible that he married a first wife at an earlier time (perhaps between 1766 and 1780). If so, he could be the actual father of John Kimbell (b. ca. 1775, Rhode Island; https://www.wikitree.com/wiki/Kimbell-181). This could explain how that John Kimbell ended up in Clarendon, Vermont, because Mary Howland had a brother Caleb Howland who was married in Clarendon in 1779.
Another possible son of such a first marriage could be Joseph Kimbell (b. ca. 1770) who appears in the 1790 Census of Clarendon (with one young son; https://www.wikitree.com/g2g/1180973/seeking-parents-john-kimbell-rhode-island-clarendon-vermont). It is uncertain if John Kimbell (b. ca. 1775) was in Clarendon as early as 1790, but if not, he could have joined his supposed brother Joseph between 1790 and 1800. John Kimball (born 1746) was still in Rhode Island in 1797 (see land record above), but sons of a first marriage could have joined Caleb Howland in Vermont.
