A boundary is a line that separates two areas or regions. In the context of this question, it refers to the agreed-upon line between the United States and Britain for the territory of Oregon.
Related terms
Territory: Refers to an area of land under control or jurisdiction of a particular country or government.
Negotiation: The process of discussing and reaching an agreement on something through conversation and compromise.
Conflict: Refers to a serious disagreement or clash between two parties, often resulting from opposing interests or beliefs.