The long distance footrace term, “Marathon” was coined to signify the general distance between the town of Marathon and the Greek metropolis of Athens. Pheidippides, an Athenian day runner/courier/soldier was tasked with the job of delivering news to the big city of Greece’s victory over Persia in the Battle of Marathon (490BC). He was said to have shouted “Nikomen” (we win) and then collapsed and died. His death was tragic but he completed the transfer information which was of paramount military strategy importance.
The actual distance traveled by Pheidippides was never verified but is estimated to have been between 24 and 26 miles- a general run between the Marathon battlefield and the middle of Athens. When the first Modern Olympic Games were planned out in 1896 the first Marathon was run as an homage to Pheidippides and his fateful journey approximately two and a half millennia earlier. The first official Marathon route was from Marathon Bridge to Olympic Stadium in Athens, a distance of 40,000 meters/24.85 miles. This first official race was won by a Greek postal worker named Spiridon Louis. He crushed the other 24 competitors by finishing the race in just under three hours (2:58:50). He was seven minutes ahead of the pack and only 9 runners (36%) completed the entire route!
The first handful of marathons were run at slightly different distances with the idea that as long as all of the runners in that particular race were running the same course, there was no need for an exact uniform distance (as long as the race was generally as long as the distance between the two cities.)
The official distance of the marathon as it is run today comes from the 1908 London Olympics. This was a course laid out through the city that ran from Windsor Castle to White City Stadium (26 miles). An extra 385 yards or approximately two tenths of a mile were added to the course inside the stadium in order for the finish line to be right in front of the royal family’s viewing box. This also began the tradition of singing “God Save The Queen” during the last mile of the race. This distance was officially adopted in 1921 by the International Amateur Athletic Federation, thus ending the slight variance in marathon lengths (the first seven modern Olympics actually had six different total distances).