logistics

logistics – n - The branch of military science and operations dealing with the procurement, supply, and maintenance of equipment, with the movement, evacuation, and hospitalization of personnel, with the provision of facilities and services, and with related matters; the planning, implementation, and coordination of the details of a business or other operation.

I was interested to learn that the Union Army of the Potomac, with about 105,000 men present in Spring of 1862, needed 600 tons of supplies daily to maintain itself. I am therefore highly skeptical of Herodotus' claim that Xerxes fielded a five-million-man army in the second Persian War (480-479 BC). McLellan had railroads and steamboats at his disposal; Xerxes had sailboats and oxcarts.