Answer:
Interpretation of the Quran employing other Quranic reference is very common because of the close interrelatedness of the verses of the Quran with one another.
If i'm not mistaken, the European Union practices a Federal government structure :)
President Andrew Jackson reason to remove the Native Americans because he wants the land for settlers to settle in and he didn't want the Native Americans to bother them and he anted the to leave but they wouldn't buge so the law stated they had to be forced and walk to what is now present-day Oklahoma Hope this helps:)