Harry saw that, according to Jackson's custom, they would attack, not wait for it.

It was yet dusky, but the firing in their front was increasing in intensity.

There was a steady crash and a blaze of light from the rifle muzzles ran through the forest.
He took an order to the Acadians to move forward behind two batteries, and as he came back he passed the Invincibles, now a mere skeleton regiment, but advancing in perfect order, the two colonels on their flanks near their head.

He also saw St.Clair and Langdon, but he had time only to wave his hand to them, and then he galloped back to Jackson.
The dusk rapidly grew thinner.

Then the burnished sun rose over the hills, and Harry saw the Northern army before them, spread across a level between the river and a spur of the Blue Ridge, and also on the slopes and in the woods.