A recommendation was made in February 1865 that the Camp be moved to Navarro county because of the exhaustion of supplies in Smith County. Obviously that was never done. Col. Ignatius Sysmanski was the CS Commissioner of exchange for the Trans-Mississippi. There is no correspondence from him relating to prisoners at Bonham. On one of the trips to the National Archives, we identified and copied all of the exchange lists from the Trans-Mississippi with the exception of the lists of the 8th US prisoners captured at San Antonio. None of them dealt with any prisoners from Bonham. These included: 1. Enlisted men taken at Galveston, 2, enlisted men captured at Brashear City in June 1863, 3. a field exchange after the engagements in the Opelousas area in November 1863, 4., an exchange of badly wounded prisoners from Mansfield and Pleasant Hill, 5, exchanges from Camp Ford in July and October 1864, and February and May 1865, and 6., exchanges from Camp Groce in December 1864.
Sysmanski was diligent in effecting exchanges as it meant returning CS prisoners back in the field. Had there been an extra thousand union prisoners in Texas, he would have pushed to trade them back.
In short, I do not believe that there were ever any Union prisoners in Bonham.