Why is the length of the marathomn 26 meters and 385 yards?

Answer 1

In the first 7 modern olympic games, there were 6 different distances used for the marathon. 40 km was used twice, including the first modern Olympics in 1896. The 1908 course in London was also originally 40 km, but was modified to finish in the stadium in front of the royal box, and was 26 miles 385 yards. This race ended in a dramatic finish with Dorando Pietri collapsing several times and being helped across the finish line ahead of Johnny Hayes, but being disqualified.

That distance was not immediately adopted as the official marathon distance, but that dramatic finish and several rematches between the two at that distance helped popularize it. It became the official distance for the 1924 Olympics.