The Oregon boundary dispute was a territorial conflict between the United States and Great Britain in the early 19th century. The disagreement centered around the area known as Oregon Country, which included present-day Oregon, Washington, and parts of Idaho, Montana, and Wyoming. Both nations claimed the region based on exploration and settlement, leading to tensions over land ownership. The dispute was resolved with the signing of the Oregon Treaty in 1846, which established the boundary at the 49th parallel. This agreement allowed the United States to gain control of the southern portion of the Oregon Country, while Great Britain retained the northern part, which is now British Columbia.