Answer:
After Christopher Columbus led the second European expedition to the Americas and discovered South America, the Spanish and the Portuguese laid claim to the entire continent save for several small areas claimed by other European powers such as the British and French.
The Europeans brought with them some dangerous diseases such as measles and small pox that the Natives had no immunity to leading to approximately 90% of the Natives dying.
The Europeans replaced the dead with African enslaved people in order to have agricultural labor as well as interbreeding with the locals and forming a mixed race class which is why South America today is a mix of races.
