See; http://supreme.justia.com/us/416/396/
In the Federal court system, the district courts are the "lowest" courts. Cases usually start in district court and are decided there. The circuit courts are courts of appeal. That means that you can appeal a district court's ruling to the circuit court (and then to the Supreme Court, if you still don't like the ruling). In that sense, the circuit courts are "higher" than the district courts.
majority opinion
The ruling is made a superior court judge in an Appellate Jurisdiction. This of course may vary from state to state and country to country. Appeals may still be made to higher courts.
yes
the ruling of state supreme courts are always the final judgment on a matter.
no because i am not with that thing.
State courts can give a ruling on state law.
Dissent
what is the supreme courts ruling in the case Plessy vs ferguson
Dissent
Dissent
Dissent