Disclaimer: am from US.
Short answer: We don't.
Longer Answer: Christianity is arguably the major religion in the United States and there is a small(ish) segment of Christianity, primarily composed of Baptists, Pentacostals, and other Evangelicals, who believe that the story in the Bible which talks about the 6 days of creation (see Genesis Chapters 1-2) means 6 literal days. How they came to this belief is a much longer answer which would require a more in depth understanding of the history of Christianity in the United States. "Young Earth Creationism" is also a rather new idea and was basically unheard of prior to the early 20th century.
This is not a mainstream view and it is not held by any Christian traditions outside of those listed above. For instance, I'm Presbyterian and the idea of "young earth creationism" is ludicrous to us. The theory of evolution is generally accepted by most Christians although we generally don't discuss it much because it's science, not theology and doesn't really haveuch of a place church. Ironically, I was raised as a Baptist and was taught "young earth creationism" growing up so I am quite familiar with it even though I don't believe in it. But again, the theory of evolution is a commonly accepted, mainstream view in the United States.
As far as what the American Education system could do to increase science literacy, that's a difficult question to answer. The education system here is very diverse and the quality and resources can vary dramatically depending on where you're located.