Grand Army of the Republic Post-when the Last Veteran died the GAR Papers would go to the GAR Department of that state.
Try inquiring at either the local or State Historical Society to see
if there are any references to the GAR Post of your ancestor still
avaiable. If not place a notice inquiring (In either local Historical
Society or on the Internet) if there are any Blommington GAR Photos
exist (Preahps your ancestor is in photo)
By the way the SUVCW (Sons of Union Veterans of the Civil War has a
project "Photos from the Past" (gallery of Union soldier photos).
Photos can be sent by email but must be JPEG