The 200th anniversary of the United States brought two years of celebrations before the actual bicentennial, on July 4, 1976. Queen Elizabeth II and Prince Phillip accompanied President Ford on a tour of the land her predecessors had lost, while a spectacular parade of ships sailed from New York City to Boston. A train of 50 wagons recreated a settlers’ journey on the Oregon Trail, while another troop re-enacted Washington’s crossing of the Delaware. Johnny Cash served as Grand Marshal of the July 4 parade in Washington D.C., which inaugurated a new Smithsonian and the city’s first subway line to...