Colonel Ardant Du Picq describes the American use of cavalry in the Civil War:
The Americans in their vast country where there is unlimited room, used cavalry wisely in sending it off on distant forays to cut communications, make levies, etc. What their cavalry did as an arm in battle is unknown. The cavalry raids in the American war were part of a war directed against wealth, against public works, against resources. It was war of destruction of riches, not of men. The raiding cavalry had few losses, and inflicted few losses. The cavalry is always the aristocratic arm which loses very lightly, even if it risks all. At least it has the air of risking all, which is something at any rate. It has to have daring and daring is not so common. But the merest infantry engagements in equal numbers costs more than the most brilliant cavalry raid.
First day of Gettysburg was too arcane for du Picq?
It’s pretty to think of a war “of destruction of riches, not of men”. T E Lawrence, John Buchan’s The Courts of Morning.