Thousands of geniuses live and die undiscovered — either by themselves or by others. But for the Civil War, Lincoln and Grant and Sherman and Sheridan would not have been discovered, nor have risen into notice. … I have touched upon this matter in a small book which I wrote a generation ago and which I have not published as yet — Captain Stormfield's Visit to Heaven. When Stormfield arrived in heaven he … was told that … a shoemaker … was the most prodigious military genius the planet had ever produced.

The Autobiography of Mark Twain (1959 edition, edited by Charles Neider).