Wars produce many stories of fiction, some of which are told until they are believed to be true. The war of the rebellion was no exception to this rule, and the story of the apple tree is one of those fictions based on a slight foundation of fact.
 Ulysses S. Grant, Personal Memoirs of Ulysses S. Grant (1885). copy citation

Context

“The head of his column was occupying a hill, on a portion of which was an apple orchard, beyond a little valley which separated it from that on the crest of which Sheridan's forces were drawn up in line of battle to the south.
Before stating what took place between General Lee and myself, I will give all there is of the story of the famous apple tree.
Wars produce many stories of fiction, some of which are told until they are believed to be true. The war of the rebellion was no exception to this rule, and the story of the apple tree is one of those fictions based on a slight foundation of fact. As I have said, there was an apple orchard on the side of the hill occupied by the Confederate forces. Running diagonally up the hill was a wagon road, which, at one point, ran very near one of the trees, so that the wheels of vehicles had, on that side, cut off the roots of this tree, leaving a little embankment.” source