A Washington Affair (1) - S3-E7
Continuity mistake: Jesse and Brian enter the President's office from The Secret passage shortly after Sen. Steward and Capt. Burgoyne leave. When the two boys hear the door rattle, Jesse whispers to Brian that somebody's coming and they race off Right. The President's desk is still in 3/4 view, and remains so as Burgoyne re-enters and goes to the desk, noticing the open cabinet door, which he checks. He hears movement and voices a threat, then goes to check the curtains only to find nothing. The camera then pans down to show Jesse and Brian hiding scared under the desk. Given the brief timespan, the two boys could not possibly have moved there without Burgyone noticing their presence.
Answer: A Cooper was someone who made various things out of wood including wooden caskets and even barrels.