The area which constitutes modern-day British Columbia is the remnants of the Hudson's Bay Company's Columbia District and New Caledonia District following the Oregon Treaty. Before joining Canada in 1871, British Columbia consisted of the separate Colony of British Columbia (formed in 1858, in an area where the Crown had granted a monopoly to the Hudson's Bay Company), and the Colony of Vancouver Island (formed in 1849) constituting a separate crown colony until it was united with the colony of British Columbia in 1866.