On 22 Oct 1761 when Joseph was 26, he married Sarah Merrill in Ipswich, MA. Born on 25 May 1741 in Rowley, MA. Sarah died in Atkinson, Rockingham County, New Hampshire, on 30 May 1823; she was 82.
Children of Joseph and Sarah (Merrill) Knight, born at Atkinson:
i. Mary Knight, b. 4 Jun 1763;
ii. Lois Knight, b. 11 Aug 1765;
iii. Abigail Knight, b. 17 Aug 1767;
iv. Joseph Knight, b. 1769;
v. Sarah Knight, b. 1771;
vi. Hannah Knight, twin, b. 1771;
vii. Martha Knight, b. 1773;
viii. Thomas Knight, b. 1777; and
ix. John Knight, b. 1780.