Ca 1780 Joseph married Elizabeth Reynolds (53338) , daughter of Lieut. Grindall Reynolds (36625) (11 Jul 1726-aft 1790) & Sarah Searle (56031) (28 Jan 1733-).420 Born ca 1760 in Bristol, RI. Elizabeth was baptized on 5 Oct 1760.328 Elizabeth died in Putney, Windham County, Vermont in Oct 1817.

Children of Joseph and Elizabeth (Reynolds) Underwood:
    i. Timothy Underwood, b. 27 Mar 1782 in Putney, VT;
    ii. Sally Underwood, b. 1784;
    iii. Joseph Underwood, b. 1786;
    iv. Phinehas Underwood, b. 1787;
    v. Polly Underwood, b.1788;
    vi. Elizaabeth Underwood, b. 1790; and
    vii. James Underwood, b. 1792.