Family background
William O’Brien was married to Elizabeth, who died 29 October 1864. He died on 8 January 1867, aged 76 years.
Local government service
William O’Brien was an alderman for Cook municipality 1864-66 and for Camperdown 1868-71.
References
The Sydney Morning Herald, 15 June 1864, p. 3, http://nla.gov.au/nla.news-article13091062