<P> A series of gold rushes in various parts of the province followed, the largest being the Cariboo Gold Rush in 1862, forcing the colonial administration into deeper debt as it struggled to meet the extensive infrastructure needs of far - flung boom communities like Barkerville and Lillooet, which sprang up overnight . The Vancouver Island colony was facing financial crises of its own, and pressure to merge the two eventually succeeded in 1866, when the colony of British Columbia was amalgamated with the Colony of Vancouver Island to form the Colony of British Columbia (1866--71), which was, in turn, succeeded by the present day province of British Columbia following the Canadian Confederation of 1871 . </P> <P> The Confederation League, including such figures as Amor De Cosmos, John Robson, and Robert Beaven, led the chorus pressing for the colony to join Canada, which had been created out of three British North American colonies in 1867 (the Province of Canada, Nova Scotia and New Brunswick). Several factors motivated this agitation, including the fear of annexation to the United States, the overwhelming debt created by rapid population growth, the need for government - funded services to support this population, and the economic depression caused by the end of the gold rush . </P> <P> With the agreement by the Canadian government to extend the Canadian Pacific Railway to British Columbia and to assume the colony's debt, British Columbia became the sixth province to join Confederation on July 20, 1871 . The borders of the province were not completely settled . The Treaty of Washington sent the Pig War San Juan Islands Border dispute to arbitration in 1871 and in 1903, the province's territory shrank again after the Alaska boundary dispute settled the vague boundary of the Alaska Panhandle . </P> <P> Population in British Columbia continued to expand as the province's mining, forestry, agriculture, and fishing sectors were developed . Mining activity was particularly notable throughout the Mainland, particularly in the Boundary Country, in the Slocan, in the West Kootenay around Trail, the East Kootenay (the southeast corner of the province), the Fraser Canyon, the Cariboo, the Omineca and the Cassiar, so much so a common epithet for the Mainland, even after provincehood, was "the Gold Colony". Agriculture attracted settlers to the fertile Fraser Valley, and cattle ranchers and later fruit growers came to the drier grasslands of the Thompson River area, the Cariboo, the Chilcotin, and the Okanagan . Forestry drew workers to the lush temperate rainforests of the coast, which was also the locus of a growing fishery . </P>

When did british columbia became a province of canada