The faint echo of shots from the skirmishers far in front showed that they had roused up an enemy.

Glasses were put in use at once.
"The Confederates are before us," said Colonel Winchester.
"So they are, and we're going to have hard fighting," said a major.
"Look what a position!" Dick said nothing, but he was using his glasses, too.

He saw before him rough ground, thickly sown with underbrush.

There was also a deep ravine or rather marsh choked with vines, bushes, reeds, and trees that like a watery soil.

The narrow road divided and went around either end of the long work, where the two divisions united again on a ridge, on which Bowen had placed his fine troops and artillery.
"I don't see their men yet, except a few skirmishers," said Dick.
"No, but we'll find them in some good place beyond it," replied Colonel Winchester, divining Bowen's plan.
It was night when the army in two divisions, one turning to the right and the other to the left, began the circuit of the great marshy ravine.
Dick noticed that the troops who had struggled so long in mud and water were eager.