On 16 May 1765 when Erastus was 20, he married Betty Doty Sherman (38034) , daughter of Robert Sherman (22420) (ca 1715-aft 9 May 1783) & Mary Oakman (18612) (3 May 170[9?]-aft 4 Oct 1749), in Marshfield, MA.123 Born on 11 Apr 1746 in Marshfield, MA.332 Betty Doty died aft 1790.

Children of Erastus and Betty (Sherman) Richards, born at Waldoboro:
    i. Jane Richards, b. 24 Aug 1765, d. 16 Feb 1834, m. ca. 1790 George Erskine;
    ii. Polly Richards, b. ca. 1768, d. 18 Sep 1829, m. 21 Jul 1789 Robert Thompson (d. 1 Mar 1849 at Warren, ME);
    iii. Betsey Richards, b. Aug 1770, d. 20 Oct 1858 at Bristol, m. John Carter (b. 1768, d. 21 Feb 1836 at Bristol)
    iv. Deborah Richards, b. ca. 1772, d. 1837 at Union, ME, m. ca. 1791 Story Thompson;
    v. Erastus Richards, b. 1 May 1775, d. 20 Feb 1807, m. ca. 1796 Isabella Thompson (b. 26 Aug 1775, d. 10 Jul 1807)
    vi. Sally Richards, b. ca. 1777, m. 5 Oct 1799 Robert Jones;
    vii. Doty Richards, b. ca. 1781, m. at Bristol 5 Dec 1805 Esther Stuart;
    viii. Huldah Richards, b. ca. 1783, d. after 1820 at Hallowell, ME, m. 1st ca. 1802 Jonathan Train, m. 2nd ca. 1807 Josiah Rollins (b. Aug 1769 at Newcastle, ME, d. 3 Mar 1851 at Hallowell); and
    ix. Robert Richards, b. 1 Oct 1786, d. 1842 at Hope, ME, m. 1st Joanna Webb, m. 2nd Margaret Newbert.