Political map of North America & the Caribbean 02 October 1843 (Oregon Dispute): By the early 1840s, American settlers, arriving overland in increasing numbers along what became known as the Oregon Trail, were beginning to challenge the dominance of Britain's Hudson's Bay Company in the jointly-occupied Oregon Country. In 1843, these settlers had enough influence to push through a pro-US provisional government (Provisional Government of Oregon), encouraging their supporters in the east to clamor for the US seizure of the entire region (Oregon dispute).