[1] By this time Sanderson had withdrawn from the partnership and his place had been taken by young William Murray who was two years younger than Roberts.
Roberts also found time to serve his community as Mayor of Dunedin and earlier as a member of the Otago Provincial Council.
On 26 January 1870, he married Louisa Jane, second daughter of the surveyor who laid out Dunedin, Charles Kettle,[2][6] and they had at least nine children.
He was deputy chairman of Union Steamship Company, when he retired in 1914 the biggest shipping line in the southern hemisphere.
[2] As well as serving as Dunedin's mayor (1889–1890), Roberts' participation in the life of the community included service in these public institutions: president of the Dunedin Chamber of Commerce, the Otago University committee including chairman of its finance committee,[2] representing Kaikorai in the Otago Provincial Council from June 1873 until its abolition in October 1876[7] and representing Deep Stream riding in the Taieri County Council.