Air Force One is the official call sign for any U.S. Air Force aircraft carrying the president, though it's most famously associated with the highly customized Boeing 747s (VC-25) used for presidential travel. The concept began during World War II, with the first purpose-built presidential plane, the Douglas C-54 "Sacred Cow," carrying Franklin D. Roosevelt to the Yalta Conference in 1945 and later serving Harry S. Truman. The "Air Force One" call sign was established in 1954 after a near-collision involving President Dwight D. Eisenhower's plane and a commercial flight, and the iconic blue-and-white livery was designed by Raymond Loewy in 1962. Over the decades, the fleet has included Lockheed Constellations, Boeing 707s, and the current VC-25A models, with a new Boeing VC-25B (a modified 747-8) entering service in July 2026, and more expected by 2027-2028. The aircraft has also hosted notable guests, such as when Richard Nixon flew with Soviet leader Leonid Brezhnev in 1973 and Ronald Reagan with Queen Elizabeth II in 1983, cementing its role as a flying symbol of the presidency.