Final answer:
Tension between the US and indigenous people in the Northwest Territory in the early 1800s was driven by several factors including British and Spanish influence, conflicts between settlers and tribes, and the formation of the Miami Confederacy.
Step-by-step explanation:
In the early 1800s, tension between the US and indigenous people in the Northwest Territory was driven by several factors. First, both Great Britain and Spain complicated the situation by encouraging Native American resistance to American settlement. This was due to their own territorial disputes with the United States. Additionally, there were conflicts between American settlers and indigenous tribes as more settlers pushed westward. The Native American nations formed the Miami Confederacy or the Northwest Confederacy to present a united front against the United States, and they refused to honor treaties signed by only one individual or group. These tensions ultimately led to the outbreak of the Northwest Indian War from 1785 to 1795.