While the U.S. President today typically flies in one of two modified Boeing 747-200s, these aircraft are not the only Air Force Ones. In fact, it's a call sign that refers to any Air Force aircraft currently carrying the president. There have been a wide range of aircraft that carried the illustrious "Air Force One" moniker over the years, with some remarkable paint jobs and liveries too. But some exclusive presidential aircraft existed prior to the call sign's establishment. One notable example is the propeller airplane that belonged to Harry Truman, which was only the second aircraft specifically designed to...