Adam Badeau, Military history of Ulysses S. Grant from April 1861 to April 1865. Volume 1

It was this which induced commanders to risk raids and marching columns far into the wilderness, leaping from one base of supplies to another, hundreds of miles away. Grant's march through the forest till he passed below Vicksburg, his crossing the almost impassable Mississippi, an enterprise deemed so difficult that the rebels hardly considered it in their arrangements for defence, his throwing his columns into the wilderness in the rear of the city, and suddenly appearing before Johnston and beating him in detail, then driving Pemberton into Vicksburg, and striking for a new base on the Yazoo—were all due to the conclusion he arrived at, that the rules of strategy laid down in the books and applicable in a champaign country, should be violated in the wilderness. The condition of things was unprecedented in the wars we read of; his mode of overcoming such unknown obstacles had to be, and was, original. His mind, indeed, was never much inclined to follow precedents, or to set store by rules. He was not apt to study the means by which other men had succeeded; he seldom discussed the campaigns of great commanders in European wars, and was utterly indifferent to precept or example, whenever these seemed to him inapplicable. He thus disappointed his greatest subordinates, and, indeed, even the general-in-chief and the government, as well as the enemy, none of whom anticipated the success of his plans, or foresaw the means by which that success was to be accomplished.

But Grant remembered and applied the lesson taught him at Holly Springs. He had learned there that an army could live without a base; and now with a larger army, and for a longer period, and amid