Is there evidence of there being no design in nature?
the second part doesn't really belong in a science curriculum. History class would probably be a better fit
Should the science curriculum contradict the history class?
It's up to those who advocate design to bring evidence to support it, rather than for those who dispute it to disprove it. That being said, nobody has really managed to describe what such evidence for design would even look like, let alone whether there actually is any.
Should the science curriculum contradict the history class?
Your particular wording is helpful here - "our culture is founded on a belief in a creator who endows us with inalienable rights" is a perfectly true statement. It's also different than saying "there is a creator who endows us with inalienable rights". The first one is true, as I said, but it properly belongs in a study of culture and society, not of science. The second one may or may not also be true, but it is contentious enough that it will never be a part of any government-sponsored classroom, because most people don't want it to be part of such a classroom.