response: The distance did not become standardized until 1921 for the marathon
history: I have been running for 1.5 years to work my way up to a marathon.  Its taking a while! Very interesting. Do you think you can run the total Marathon distance of 26.219 miles? Sure, but I'm not there yet. I can go about 12 miles. I wonder if a marathon has ever been shorter when they were first started.
knowledge: The marathon was one of the original modern Olympic events in 1896, though the distance did not become standardized until 1921.