Career
He was named to the Senate of Canada in 1918. Born in Lochaber, Nova Scotia, he started in the railway business as a railway labourer during a period of great expansion of railways in Canada, eventually becoming a railway builder. In 1891 he went bankrupt after a disastrous contract for the Canada Atlantic Railway.
He rebuilt his business through construction contracts and opened the O'Brien silver mine in Cobalt, Ontario in 1903. He was the Temiskaming and Northern Ontario Railway's commissioner from 1902 to 1905. His influence in Renfrew and the surrounding area was everywhere, including a dairy, woollens and knit factories, and saw and planing mills.
O'Brien's philanthropic acts were equally numerous and diverse. Many of the heritage buildings in Renfrew can be traced to his patronage. He donated the O'Brien Cup to the league, which was used until 1950 by the National Hockey League and is in the collection of the Hockey Hall of Fame.
He served as Senator for Ontario from 1918 to 1925. He died in 1940 in Renfrew.
