Spanish explorers had taken the lead in the Pacific Northwest coast, with the voyages of Juan José Pérez Hernández in 1774 and 1775. By the time the Spanish determined to build a fort on Vancouver Island, the British navigator James Cook had visited Nootka Sound and charted the coast as far as Alaska, while British and American maritime fur traders had begun a busy era of commerce with the coastal peoples to satisfy the brisk market for sea otter pelts in China, thereby launching what became known as the China Trade. In 1789 war threatened between Britain and Spain on their respective rights; the Nootka Crisis was resolved peacefully largely in favour of Britain, the much stronger naval power at the time. In 1793 Alexander MacKenzie, a Scotsman working for the North West Company, crossed the continent and with his Aboriginal guides and French-Canadian crew, reached the mouth of the Bella Coola River, completing the first continental crossing north of Mexico, missing George Vancouver's charting expedition to the region by only a few weeks. In 1821, the North West Company and Hudson's Bay Company merged, with a combined trading territory that was extended by a licence to the North-Western Territory and the Columbia and New Caledonia fur districts, which reached the Arctic Ocean on the north and the Pacific Ocean on the west.

The Colony of Vancouver Island was chartered in 1849, with the trading post at Fort Victoria as the capital. This was followed by the Colony of the Queen Charlotte Islands in 1853, and by the creation of the Colony of British Columbia in 1858 and the Stikine Territory in 1861, with the latter three being founded expressly to keep those regions from being overrun and annexed by American gold miners. The Colony of the Queen Charlotte Islands and most of the Stikine Territory were merged into the Colony of British Columbia in 1863 (the remainder, north of the 60th Parallel, became part of the North-Western Territory).