Why do chromosomes appear as x shaped structures durng the early part of mitosis, but not at the end?

Because in second phase of mitosis (which is metaphase) the chromatids meet each other in the middle, creating the X shape. it doesn't have an X shape in the end because in the 3rd phase of mitosis (which is anaphase) the chromatids split apart from each other.

  citizens of individual states were also citizens of the united states.