> I doubt Columbus's conquest was uniquely brutal for its time

"Uniquely brutal" is a very high bar. I trust you didn't mean it as a rhetorical technique to require demonstration that no one else was as brutal as he was, before acknowledging that he was brutal even for his time?

Since you argue that Columbus was unique in "that he discovered America", then he is also unique for being the first European to lead slave raids of indigenous Americans, and the European to introduce the genocidal encomienda system.

And he was brutal. If Bobadilla's accusations of Columbus's brutality are correct, then Columbus's conquest was exceptionally brutal, even to other Spaniards of the time.

From Wikipedia at https://en.wikipedia.org/wiki/Christopher_Columbus

"Bobadilla reported to Spain that Columbus once punished a man found guilty of stealing corn by having his ears and nose cut off and then selling him into slavery. He claimed that Columbus regularly used torture and mutilation to govern Hispaniola.[l] Testimony recorded in the report stated that Columbus congratulated his brother Bartholomew on "defending the family" when the latter ordered a woman paraded naked through the streets and then had her tongue cut because she had "spoken ill of the admiral and his brothers"."

Columbus was removed as Governor of the American due to these accusations, though later pardoned by the royals.

When do we teach this history of Columbus in school?

> and kicked off the events that led to the formation of the US

What an odd focus. Using the exact same argument, Henry the Navigator also kicked of the events that lead to the formation of the US, because of his work to initiate what is now called the Age of Discovery.

And he was unique for that.

When is Dom Henrique day?

There are definitely historical records that claim that Columbus was unusually bad even for his time, like the works of Bartolomé de las Casas.