There are 9 Federal court circuits each with a Circuit Court of Appeals. Each SC Justice ‘oversees’ and assists one of the Federal circuits...Helping with communications, standardization, ensuring funding, etc.
They were originally called circuits because judges would travel a ‘loop’ around the courthouses in the area they were assigned. They would travel a circuit.
States also had them - especially larger less populated ones.
Have always felt making the circuit courts stationary removed the judges from being near the people and they should be forced to travel again.
Thank you for the explanation. Adds credence to the original message.
There are 11 Circuit Courts, plus the DC Circuit. I imagine a few Justices oversee more than one circuit.