The exhibit will give the public its first glimpse of some of the artifacts in the archives of former President George W. Bush.
Along with the bullhorn, visitors will also see the pistol taken from Saddam Hussein when he was captured.
The free exhibit, "Breaking New Ground: Presenting the George W. Bush Presidential Center," opens Saturday and runs through Feb. 6 at the Meadows Museum on the campus of Southern Methodist University, where the center will be built.
Ground will be broken next month on the center, which will include the presidential library and the George W. Bush Institute. The center is expected to be open by early 2013.