Explain the significance of choosing the 49th parallel as the boundary between Canada and the United States.

Great Britain wanted a border that followed the Columbia River to the Pacific  Ocean.

Since 1818, the US and Britain jointly occupied the territory that is now Oregon, Washington, and Idaho and parts of Montana, Wyoming, and British Columbia. Once the boundary was established at the 49th Parallel, the United States officially expanded to the West Coast.

Explanation: Took the quiz

they died because of a disease during the first spanish colonies.

spanish executed counts egmont and horne in brussels.