Answer:
According to treaties signed in 1818 and 1827, the United States jointly occupied Oregon with Great Britain.
Step-by-step explanation:
The territory of Oregon was originally claimed by Great Britain, France, Russia and Spain; the Spanish claim was resumed as of 1819 by the United States. The extension of the area claimed was imprecise at first, evolving over decades in the borders established in the 1818 treaty between British and Americans.
The British claimed the entire Oregon territory, that is, they carried their claim to the south to the 42nd parallel north, which had been the limit agreed in 1819 between Spain and the United States in the Adams-Onis Treaty. The dispute between Great Britain and the United States was resolved peacefully, and until 1846 the United Kingdom -in factual, England itself- and the United States, through the Anglo-American Convention of 1818, exercised a condominium over the entire Territory of Oregon, also ensuring the inhibition of possible Mexican or Russian claims.