Growing up in the 80’s and 90’s, Columbus was celebrated as a hero in school, heralded for being the one who “discovered” the America’s. Now he’s remembered as the one who started the genocide of an entire continent. That transition in popular opinion only took about 25-30 years. Was he merely an explorer who served as a catalyst in something that would happen eventually anyway (the Americas being settled by Europeans). Was he a savage conquerer? What kind of man was he?
There's always more to say but these may help.
First, I provide some background on why he was/is heralded in American public schools here ("When did American students start saying the pledge?", here ("Why are we taught a false story about Christopher Columbus?"), and here ("Why do schools teach fake or incomplete versions of history to students in the first place?")
Second, /u/snapshot52 provides an in-depth exploration of Columbus in this Monday Methods - Indigenous Peoples Day and Columbus Day: Revisionist? (There are also several answers about Columbus on Snapshot52's profile.)
Third, some context on the genocide of Indigenous Americans in this question, "How would one classify Native American Genocide?"
Also, a short look at how "judging" people from the past, "When studying historical figures, how true is the phrase "people should be judged by the standards of their time" and is it unfair to hold historical figures (like Churchill or Columbus) up to the standards of modern times?".
Finally, this question, "Christopher Columbus was arrested and ostracised for a long list of well documented tyrannical and brutal acts in the New World, and for incompetence as governor of Spain's earliest colonies. How did he go from a disgraced figure to one who is celebrated by statues, and even his own holiday?" includes lots of answers from different contexts.