Christopher Columbus was not a hero. He was greedy for Native American gold. This quote from his 1492 journal demonstrates his self-importance and regard for the natives: "I could conquer the whole of them with fifty men and govern them as I pleased." He returned to America a second time to enslave the natives, to disfigure those that denied him and his men, and brought disease. He was a pedophile. He opened the door to the transatlantic slave trade.
Bartolome de las Casas, an explorer like Columbus, became an advocate against slavery of any kind during this same time frame. He was nicknamed "Defender of the Indians."
"Christopher Columbus left his home and found a new world. Bartolome de las Casas left his home and found his humanity." -- Matthew Inman