 Hamilton succeeded as 7th Earl of Abercorn at his father's death in 1734.He was sworn a Privy Counsellor in Great Britain on 20 July 1738 and a Privy Counsellor in Ireland on 26 September 1739.On 17 October of that same year, George II issued a royal charter to the nation's first orphanage for abandoned children, the Foundling Hospital, of which Abercorn was a founding Governor.