At an early stage in his life he recognised the necessity for scenic reserves and recreational areas in London and he was appointed a Director of the Kew Botanical Gardens.
Dr. Chapman was charged with appointing various staff (including a constable and a matron for single females) from the "most intelligent of the steerage passengers".
[3] As they were not sure of the building possibilities in the new colony, Dr Chapman brought the sections of a house to be erected when they arrived, as well as furniture to furnish it with.
From Port Cooper, the family went to Christchurch where Dr Chapman had purchased a 50-acre (20 ha) block of land on Lincoln Road, Addington, from the Canterbury Association for 150 NZ pounds.
William and Sarah's son, John Alwent Chapman, never married and became a businessman, moving to Dunedin probably in the early 1870s.