John James Dixwell was the son of Esther Sargeant Dixwell [1776-1865] and John Dixwell, and the great-great-grandson of Epes Sargent, the sitter for a portrait by John Singleton Copley now in the NGA (1959.4.1). Epes, ancestor of painters John Singer Sargent and Henry Sargent, was born in Gloucester, Massachusetts. He was a graduate of Harvard College, a merchant and a Congregationalist. In 1720 he married Esther MacCarty [1701-1743] and was appointed justice of the peace of Essex County, a commission he held six times. After the death of his first wife, he married Katherine Winthrop Browne, in 1744. By 1750 he and his sons owned much of the land in Gloucester. In 1761 he was elected to the Great and General Court, the legislative body of colonial Massachusetts.
Sargent, Emma Worcester and Charles Spraque Sargent. Epes Sarent of Gloucester and his Descendants. Boston and New York, 1923: 6-8.
Shipton, Clifford K., ed. Sibley's Harvard Graduates. Vol. 5, Biographical Sketches of those who attended Harvard College in the Classes 1701-1712. Boston, 1937: 645-646.