He had given some attention to social questions: his suggested new route via the Red Sea and Torres Strait for immigrant ships reduced the time of the voyage by half, and in 1878 he advocated a reformatory for girls under fourteen years of age. But his chief private interests were horse-racing and athletics. A foundation member and a committee-man of the Queensland Turf Club for over thirty years, he was also a committee-man of the Queensland Club. On 28 June 1864 in Brisbane Seymour had married Caroline Matilda (d.1884), daughter of William Anthony Brown, sheriff of Queensland; they had six daughters. He married Sara Jane Stevenson, aged 23, on 6 June 1888; of their two sons, one became a well-known engineer in Kuala Lumpur. He died on 31 January 1916 in London.