Well this is very interesting. I researched (and continue to do so) Camp Groce and compiled a book about it back 1999. I have a lot of material from the National Archives and many other sources plus what I have accumulated since. I have never found any reference to any federal prisoners being held anywhere but Camps Ford, Groce and Verde in Texas.

The POWs that were transferred from Camp Ford to Camp Groce on or about August 15, 1864 included many POWs from the battle of Marks Mills, Arkansas, but the total number sent to Camp Groce was only about 506. I think that the decision was made to sent the overflow at Camp Ford to Camp Groce since the group included troublemakers as well. There was already a stockade at Camp Groce and was able accommodate more prisoners, but transportation limitations at Camp Ford prevented more from being sent to Camp Groce.

I do not think that any POWS were sent to Bonham due to no stockade there. Escapes at Camp Ford were numerous and overcrowding was a serious problem there, so the only viable solution was Camp Groce.