The Nootka Conventions were a series of three agreements between Spain and Great Britain in 1790 which averted a war between the two countries over overlapping claims to portions of the northwestern coast of North America. The claims of Spain dated back nearly three hundred years to the papal bull of 1493 which had divided the world, and had granted to Spain the exclusive rights to settle the Pacific Coast of North America. This papal bull was not recognized by Great Britain (which was governed by Protestants) or by Russia (which was governed by Orthodox Christians).
The dispute began when Spain, in defense of its claim, seized property settled by British subject John Meares on Nootka Island, leading to a confrontation between Spain and Britain known as the Nootka Crisis which threatened to trigger a major imperial war for control of the Pacific, and, in practice, for western North America. Russia was also a party of interest, as their prior trading presence and separate claim extended much farther south of Nootka to California, and was in fact the reason Spain was attempting to solidify its claims through exploration and settlement.
The Nootka Conventions of the 1790s, negotiated by George Vancouver and his Spanish counterpart Juan Francisco de la Bodega y Quadra prevented the dispute from escalating to war. The Spanish concessions did not give up claims, only allowed other parties to trade at Nootka Sound, where a Spanish fort had been in operation. As of the Conventions the Spanish fort at Nootka Sound was available for occupation by any power, be it Russia, Britain or should Spain desire to return.
The fledgling United States had no claim in this area at the time. Spanish rights in the area were later acquired by the United States in the Adams-Onís Treaty signed in 1819. The United States argued that it acquired from Spanish rights to exclusive ownership; this position led to a dispute with Britain known as the Oregon boundary dispute. This dispute was not in fact resolved between the United States and Great Britain until the signing of the Oregon Treaty in 1846, dividing the disputed territory, and establishing what later became the current international boundary between Canada and the United States.
Although the Nootka Conventions theoretically opened the Pacific Northwest coast from Oregon to Alaska to British colonization, the advent of the Napoleonic Wars distracted any efforts towards this (as recommended by Vancouver at the time) and the proposed settlement colony in the region was to be abandoned. The Hudson's Bay Company, the remaining British presence in the region, was averse to settlement and any other economic activity than its own, such that settlement and resource development did not take place to any degree until the Fraser Canyon Gold Rush of 1858, which formalized British claims on the mainland still residual from the Nootka Conventions into the Colony of British Columbia.