Some of this is due to the character of the commanders.

One man is full of dash, and goes forward at once; another is timid, or at least over-cautious, and advances slowly; a third stops to recall some outlying detachments, or to make elaborate preparations.

The result is, the outer army has lost its strength and is always beaten in detail.

One portion is sure to be defeated before the others arrive.

We shall have occasion to refer to this principle again in reference to the battle of Gettysburg.