Centennial Anniversary Henry Flagler’s Florida Keys Over-Sea Railroad Blog Team An undated photograph shows the Henry Flagler's Florida Keys Over-Sea Railroad train on the Long Key Viaduct. Jan. 22, 2012, is to mark the centennial anniversary of the first train's arrival into Key West and the completion of the Over-Sea Railroad project. A series of events in the Florida Keys to mark the occasion are underway and more are planned. Photo courtesy of the Monroe County Public Library.