Fort Langley was established by the Hudson's Bay Company in 1827 on the lower Fraser River, within the territories of Coast Salish peoples, especially Kwantlen communities. Company governor George Simpson wanted a post closer to the Pacific coast and the river's agricultural and trading potential. The first fort stood several kilometers downstream from the present site. It entered an already active Indigenous economy and diplomatic landscape; fur trading depended on local knowledge, suppliers, food networks, and relationships rather than on Europeans opening an unused frontier.

Flooding and poor ground encouraged the company to move the post upstream in 1839. The rebuilt palisaded complex included storehouses, workshops, residences, and a trade shop. Employees came from varied backgrounds—Scottish, English, French Canadian, Métis, Kanaka or Hawaiian, and Indigenous—and many formed families with local women. Salmon soon rivaled furs in importance. Workers salted and packed fish in barrels for export to Hawaii and other markets, while farms supplied grain and livestock to coastal posts. Cranberries and other products broadened the enterprise.

The Oregon Treaty of 1846 fixed the international boundary at the forty-ninth parallel, leaving the company's main Columbia River depot at Fort Vancouver in American territory. Fort Langley consequently gained strategic importance as a British supply point, and the company developed routes linking it to the interior. The Fraser River gold rush of 1858 transformed the region almost overnight as thousands of miners arrived. Colonial officials feared disorder and American annexation, prompting Britain to establish a separate mainland colony.

On 19 November 1858, Governor James Douglas proclaimed the Colony of British Columbia in the fort's Big House. The event gave Fort Langley a reputation as the colony's birthplace, although New Westminster soon became the capital and the fort never served as one. The ceremony also represented the assertion of British sovereignty over Indigenous territories without treaties across most of the mainland. Gold-rush commerce briefly boosted business, but miners bypassed the post, private merchants competed, and regional transport patterns changed.

Hudson's Bay Company operations declined, and the company sold the property in 1886. Most buildings disappeared through fire, decay, relocation, or reuse; the surviving storehouse, dating from the 1840s, became the material core of later preservation. Community advocates promoted the site's importance, and the federal government acquired land and opened a historic park. Reconstruction of palisades and buildings created a legible fort landscape, while archaeological and documentary research refined understanding of work, trade, and the many peoples connected to the post.

Fort Langley became a national historic site and today is managed by Parks Canada. Demonstrations, exhibits, reconstructed spaces, and the original storehouse interpret fur, salmon, farming, gold, and colonial government. Recent approaches give greater attention to Kwantlen and other Indigenous perspectives, mixed families, and laborers who earlier commemorations overlooked. The site matters not simply for one proclamation, but because it reveals how corporate trade, Indigenous relationships, global markets, migration, and imperial boundary-making converged on the Fraser River and helped shape British Columbia. The fort's reconstructed order is most useful when it prompts questions about the much less orderly encounters that occurred around it.