Joshua married Mary.
Joshua and Mary Sylvester had the following children, born at Pownalborough, ME:
i. Mary Sylvester, b. 30 Jun 1739;
ii. Lydia Sylvester, b. 10 Sep 1740;
iii. David Sylvester, b. 13 May 1742;
iv. Samuel Sylvester, b. 20 Dec 1743;
v. Sarah Sylvester, b. 25 Mar 1747;
vi. Lucy Sylvester, b. 23 Sep 1750;
vii. Jane Sylvester, b. 24 Oct 1752;
vii. Elizabeth Sylvester, b. 24 Apr 1754; and
ix. Rachel Sylvester, b. 14 Jun 1756.