How come the Indians were at a disadvantage against the Spanish conquistadors?

Ineed answers 5 and 6 on my social studies homework reply to this question i posted

How did african americans the union during the civil war? a. by serving as representatives in congress b. by enlisting in the military to fight c. by organizing massive slave revolts in the south d. by negotiating for peace with the confederacy

How influential do you think athenian democracy was on our representative democracy in the united states?