What song is based on a true story?

There are, but there are horrible shunts of historical license. The popular song Convoy somehow convolutes the D-day battle ( The darkened moon on the sixth of June) with of all things the Battle of Hamel ( which was literally fought on the Fourth of July- because we had 85 trucks in all- the Battle of Hamel involved 85 RA Mark V tanks!- but from there it is involved with a trucking job action. There are other distortions in such historical songs as Battle of New Orleans, Indiana Wants me, a gangster type thing, and others. Folk songs are not noted for historical accuracy!- which is understating things.