SS-100-X is the U.S. Secret Service code name for the Presidential limousine used by the 35th President of the United States, John F. Kennedy. It is the car that Kennedy was riding in when he was assassinated in Dallas, Texas, in 1963. The design was based on a 1961 Lincoln model 74A convertible worth $7,347, later modified to Secret Service specifications by Ford Motor Company's Advanced Vehicles Group, and Hess & Eisenhardt of Cincinnati, Ohio. Together, these two companies created one of the most modern open parade limousines of its day. The limousine was presented to the White House in March 1961, after modifications that cost the United States government approximately $200,000.