I'm a big fan of Marathons. I love to run them! They are just over 26 miles and are exhilarating. 
I commend you for your dedication.  How long do you have to train for a marathon?
It usually takes me some time to train, but on top of it being an aerobic activity it's also something that requires a lot of mental strength and stamina.
I can imagine.  When did people start running marathons?
Well, it was one of the original Olympic events in 1896, so they have been around for quite a long time. The distance didn't become standardized until 1921.