The Tehran Conference, November 143: Stalin, Roosevelt, and Churchill; the first meeting of the Big Three, where the main agenda item was the long-awaited Second Front in Europe. To attend the conference, President Roosevelt secretly crossed the Atlantic aboard USS Iowa, to which various modifications had been made to accommodate him such as an elevator and a special bathtub, making the Iowa the only Navy ship to have a bathtub on board.

1. Tehran Conference, Wikipedia, accessed 14 June 2018.
2. President Roosevelt's remarks to the Crew on Leaving the USS Iowa, American Presidency Project, University of California at Santa Barbara.