The parole was instituted during the early years of the war as part of the POW exchange program. When a POW was identified for "exchange," he would be paroled, that is released and sent to a special parole camp where he remained until he was officially exchanged. The parole, a signed document, allowed a POW to safely traverse enemy lines to get back to his own side. While on parole, the holder was honor bound not to spy, commit acts of sabotage or rejoin his unit and take up arms. Working through an administrative Cartel, former POW's now back on their own side would be informed when they were formally "exchanged," which was on a one-forone basis (one US captain for one CSA captain, etc). The Union stopped exchanging POWs in 1863 and substituted the Amnesty Program which freed a POW or deserter. These individuals swore allegience to the US and were kept in Union territory and not allowed to cross back over to CSA lines. The Oath operated through 1864. The concepts become fuzzy during 1865. For political less humanitarian reasons, the Union reinstated the exchange program in March of 1865. The Confederate POWs released at that time were "paroled," many released in the Richmond area. At Appomattox, soldiers assigned to the Army of Northern Virginia received "paroles" so that they could safely cross Federal lines in the deep South. This was not an exchange. These men laid down their arms and by the conditions of the surrender were expected to go home as civilians. After the war, Union POW camps were filled with captured soldiers. Most had to sign an Oath of Allegience in order to be released. This was the same Oath that previously defectors and deserters had signed. The people managing the state pension commissions knew the difference.