His maternal grandfather was Daniel Jenckes (1701–1774), a judge from a prominent family.

[1] Both Nicholas Brown Jr. and his father were members of and large donors to the First Baptist Church in America.

Brown Jr. graduated from the College of Rhode Island and Providence Plantations in 1786.

[2] He was married twice; in 1791 to Ann Carter (1770–1798), daughter of John Carter (1745–1814), a prominent printer in Providence, and in 1801, to Mary Bowen Stelle (d. December, 1836), daughter of Benjamin Stelle, Esq.

[3][4] His children were:[5] After his death September 27, 1841, Brown was interred in North Burial Ground in Providence.