He was the ninth son of John Ross (fifth son to a second wife, Elizabeth Fullarton), an excise officer in Portuguese Glasgow of narrow means and a probable descendant (via the Rosses of Kirkland and Tartraven) from Ninian Ross, 3rd Lord Ross.
He acquired a Jamaican mistress, Elizabeth Foord, a quadroon slave whom he later freed and by whom he had several children. In 1782, with his fortune made, Ross returned to Scotland, where he was elected an Honorary Burgess of Glasgow and purchased an estate at Rossie, near Montrose, on which he later built a large house, Rossie Castle. In 1790, Ross embarked on a correspondence with William Wilberforce, which led to his giving evidence before the Select Committee of the House of Commons in support of the abolition of the slave trade.
"Having now mentioned the principal facts contained in the evidence offered to Parliament by the petitioners of Great Britain, in behalf of the abolition of the slave trade, we cannot close this compilation better than in the words of Mr Hercules Ross: he says, “finally, as the result of his observations and most serious reflection, he hesitates not to say, that the trade for slaves ought to be abolished, not only as contrary to sound policy, but to the laws of God and nature.
And were it possible, by the present inquiry, to convey a just knowledge of the extensive misery it occasions, every Kingdom of Europe must unite in calling on their legislatures to abolish the human traffic…”
Horatio (1801-1886) subsequently became a celebrated sportsman, being the best rifle shot of his day, and a pioneer photographer.
The evidence of Ross, as a former member of the planter society whose basis he now condemned, was considered of particular benefit and he was in consequence made an honorary and corresponding member of the Society for the Abolition of the Slave Trade.
