Palestine became a contested territory during the 20th century in part
because:

federal appellate courts are called courts of appeals. cases can be further appealed to the u.s. supreme court. cases are heard for the first time in a trial court. if either party disagrees with the decision in the trial court, they can appeal, asking a higher court to review the decision.

the population grew a lot and was making more money

the constitution of the united states gave congress the absolute authority over immigration laws