I mean , come on! Christofer Columbus was not the first person on american soil. Recently there was a discovery of human remains of 15,000 years ago in the mountains of oregon that are to be asian and siberian.
The textbooks you refer to are generally old and were written with a Euro-centric orientation. Meaning, the first European who made a well-documented visit to this continent and came back and spread the word, was Christopher Columbus.
If you look at more modern textbooks, they generally acknowedge that the American Indians were here first, and that they were other explorers before Columbus, most notably the Vikings about 500 years prior.
history is written by the winners, never forget that everything that you consider to be accepted and the norm is probably not the truth, it has been mashed up and force fed to you until you have accepted it.
it isn't the government that's lied. It's the conventions of our boring an unthinking educational system. Things get repeated to kids so kids can repeat them and pass tests. It's easier to identify Columbus than to think about the reality of this continent and the people that have lived here.
The government could not care one way or the other that you credit Columbus or Erickson, or simply recognize that the whole cliche is from a European viewpoint. All the government wants is for you to get off their back, and quit asking all those questions.