After the creation of the province of Ontario in 1867, the first district to be established was Thunder Bay District, Ontario of the Privy Council in 1884 and confirmed by the Canada (Ontario Boundary) Act, 1889 of the Parliament of the United Kingdom.
After the creation of the province of Ontario in 1867, the first district to be established was Thunder Bay in 1871 which until then had formed part of Algoma District. Ontario's right to Northwestern Ontario was determined by the Judicial Committee of the Privy Council in 1884 and confirmed by the Canada (Ontario Boundary) Act, 1889 of the Parliament of the United Kingdom.