Sorry to correct you but...
At the 1908 Olympic Games in London, the marathon distance was changed to 26.2 miles to cover the ground from Windsor Castle to White City Stadium, with the 2.2 miles added on so the race could finish in front of royal family's viewing box. This added two miles to the course, and is the origin of the Marathon tradition of shouting "God save the Queen!" (or other words relating to the Queen) as mile post 24 is passed.
