Today is the the traditional day celebrated when Columbus made landfall in the Americas on 12 October, 1492. He was widely venerated in the centuries after his death, but public perceptions have changed as recent scholars have given attention to negative aspects of his life.
When I was growing up in California 60+ years ago, Columbus was celebrated along with the California missionaries. Much of that has changed. Columbus is now derided for his treatment of indigenous peoples as are the missionaries.
To provide some more history, very few people know of Bartolomé de las Casas (1484 – 1566) who spent 50 years of his life actively fighting slavery and the colonial abuse of indigenous peoples. His efforts resulted in several improvements in the legal status of the natives, and in an increased colonial focus on the ethics of colonialism. Las Casas is often considered to be one of the first advocates for a universal conception of human dignity (later human rights).
And speaking of California, not many know about the California Genocide, which refers to the violence, relocation, and starvation that led to a decrease in the indigenous population of California as a result of the US occupation of California. The indigenous population of California under Spanish rule dropped from 300,000 prior to 1769, to 250,000 in 1834. After Mexico won its independence from Spain, the indigenous population suffered a much more drastic decrease in population to 150,000. The period immediately following the US Conquest of California has been characterized by numerous sources as a genocide. Under US sovereignty, after 1848, the Indigenous population plunged from perhaps 150,000 to 30,000 in 1870 and reached its nadir of 16,000 in 1900.