This "big business" pushed Americans to struggle to survive horrible winters and starvation in Oregon Country.
1. Oil
2. Agriculture
3. Fur-trapping
4. Shipping

3. Fur-trapping

Explanation:

Fur trapping involves catching animals primarily for the purpose of its furs.

During the winter of the early 1600s there were some issues with bringing in goods into the United States. This period was known as ‘Starving Time’ .

The fur trapping helped citizens to use these furs gotten from the animals to make it clothes suitable for the harsh winter conditions. It also provided a source of food for the citizens.

the indians crossed artificial boundaries, setting the stage for conflict