Columbus Day is celebrated on this day even though Christopher Columbus' expedition first sighted the land later called America on Oct 12, 1492. We're supposed to feel extremely guilty about bringing death and destruction to the aboriginal peoples as well as land theft, torture, mutilation, and enslavement. Except that none of that is unique to the European paradigm vis a vis Native Americans (note: the preferred term of Native Americans is "Indians.") It is true European immigrants obtained land from Indians by purchase, fraud, trade, and conquest, killed, tortured, mutilated, and enslaved Indians, but the Indians did the same amongst themselves and had done so for thousands of years before Columbus was even born.
"The Indians" is a misnomer in the sense there was no singular united group of Indians from sea to shining sea. Rather, there were well over the 500 Nations modern Indians claim, and they were constantly at war with one another that included what is today called torture and genocide - that's a large reason for only 500 Nations by the time Europeans showed up. Incidentally, at the time, the Europeans were Spanish and Portuguese later to include French, Dutch, Germans, and English. Much later, that is to say, today, Europeans are specifically and singularly, English.
At least one Indian saw the similarity of the European and Indian land gains and hypocrisy of the Indian claims they were different from the white man. At the Laramie Peace Conference in 1851 also called the 1851 Horse Creek Treaty, Black Hawk, an Oglala Sioux, said:
“Father, if there is anything I do know, it is this country, for I was raised in it, with the interpreters and traders. You have split the country, and I don’t like it. What we live upon, we hunt for, and we hunt from the Platte to the Arkansas, and from here up to the Red Butte and the Sweet Water. The Cheyennes and Arapahoes agree to live together and be one people; that is very well, but they want to hunt on this side of the river. These lands once belonged to the Kiowas and the Crows, but we whipped these nations out of them, and in this we did what the white men do when they want the lands of the Indians. We met the Kiowas and the Crows and whipped them, at the Kiowa Creek, just below where we now are. We met them and whipped them again, and the last time at Crow Creek. This last battle was fought by the Cheyennes, Arapahoes and Oglalas combined, and the Oglalas claim their share of the country.”
Like it or not, we came in possession of this country the same way the Indians did - by force, fraud, and trade. For that, there is no guilt.