This discussion did not put a stop to the exchange, but while it was going on Vicksburg was captured, and the battle of Gettysburg was fought.
The first placed one of the exchange points in our hands.

At the opening of the fight at Gettysburg Lee captured some six thousand Pennsylvania militia.

He sent to Meade to have these exchanged on the field of battle.

Meade declined to do so for two reasons: first, because it was against the cartel, which prescribed that prisoners must be reduced to possession; and second, because he was anxious to have Lee hampered with such a body of prisoners, since it was very doubtful if he could get his beaten army back across the Potomac, let alone his prisoners.

Lee then sent a communication to General Couch, commanding the Pennsylvania militia, asking him to receive prisoners on parole, and Couch, not knowing what Meade had done, acceded to the request.