He was the son of John Maxwell, 1st Baron Farnham and Judith Barry.

[2] He was Prothonotary of the Court of Common Pleas between 1741 and 1800, was called to the Irish Bar in 1748 and was appointed a Bencher in 1757.

He commissioned James Wyatt, one of the most fashionable architects of the time, to design a new house.

These plans are now housed in the Metropolitan Museum of Art in New York.

They had the following issue:[2] On his death, he was succeeded by his son John James.