 Cox was educated at The King's School, Parramatta and developed extensive pastoral interests in Dubbo, Mudgee, the Warrego River District and the Liverpool Plains.He was prominent in the synod of the Anglican Church of Australia, active in local Government in the Mudgee district and a foundation member of the Royal Agricultural Society of New South Wales.Cox was elected as the representative for the seat of Wellington (County) in the first Legislative Assembly convened after the granting of responsible self-government in 1856.