Robert Hamilton of Rozelle (see Rozelle under property) was joined in Jamaica by his brother John, who became co-owner with him of the Pemberton Valley sugar plantation. On his way back to Scotland in 1739 to see his new-born son, John junior, he was lost at sea. Young John's trustees bought the Sundrum Estate for him. In 1755 Robert Hamilton sent his young nephew John Hamilton of Sundrum to Jamaica to manage the Pemberton Valley sugar plantation. In 1762 he returned to Sundrum, and in James Edward Shaw's 1953 book 'Ayrshire 1745-1950' it is claimed that in Joppa (now part of Coylton village) 'there were at one time a number of negroes, brought from the plantations in the West Indies, belonging to John Hamilton of Sundrum' who intermarried with the local population. John's eldest son, also John, succeeded him at Sundrum. That John's brother, Alexander West Hamilton, inherited Pinmore and Belleisle from his uncle Hugh Hamilton. He went out to Jamaica in 1783 to manage the Pemberton Valley and Rozelle plantations, and was there for nearly twenty years.
He then returned to Ayrshire, and soon after the abolition of slavery in 1834 Colonel Hamilton, as he now was, agreed with the Jamaican parents of a young boy, Alexander Waters, that he would be brought over, would be educated and taught a trade, and would then return to work in Jamaica. (After emancipation in 1834 slaves were still bound to their masters under an 'apprenticeship' scheme for four to six years, although this had been ended by 1838.) Alexander, however, having become a stonemason and builder, married and settled down on the Sundrum Estate. Described as a 'man of colour', he died there in 1894 aged around 65, a respected member of the community. It may be that the account in Shaw's book is actually a garbled memory of Alexander and his descendants.