Vintage Map of the Battle of Gettysburg Coffee Mug Pencil Cup - Black

This mug is large & heavy and I believe it may be stoneware. It came from the National Archives. It has details about the map on the bottom. It has a small chip is the rim so maybe it can be used as a pencil cup. I am not sure, but I believe it is out of print. I'm downsizing my kitchen and must sell.