[1][2] Hamilton was a reputed antiquarian and genealogist, praised by George Crawfurd, and an acknowledged supporter of Alexander Nisbet's System of Heraldry (1722).
[1][2] Hamilton left in manuscript an Account of the Shyres of Renfrew and Lanark, which went to the Advocates' Library, Edinburgh.
In 1832 it was published as one of the volumes of the Maitland Club, edited by William Motherwell, and consists of brief topographical descriptions of the principal castles and mansions in Renfrewshire and Lanarkshire, with genealogical information on local families.
He did not assume the dignity, however, and his eldest son, who claimed the title, became seventh Lord Belhaven.
His son Robert Montgomery Hamilton (1793–1868) was eighth Lord Belhaven and Stenton.