President Barack Obama waves goodbye as he boards Air Force One on his trip to Cuba from Joint Base Andrews, Md., March 20, 2016. Obama’s visit marks the first time a sitting U.S. president has traveled to the island nation since Jan. 16, 1928 when President Calvin Coolidge visited Havana, Cuba to address the Sixth Annual International Conference of American States. (U.S. Air Force photo by Senior Airman Joshua R. M. Dewberry/RELEASED)