He was married to Ann Carter (1770--1798), daughter of John Carter (1745--1814), a prominent printer in Providence. Together, they had: Nicholas Brown III (1792--1859), who married his 2nd cousin, Abby Mason (1800-1822), daughter of James Brown Mason (1775--1819), in 1820. After her death, he married Caroline Matilda Cements (1809-1879) in 1831.
Abby Mason
Caroline Matilda Cements