The Army of Northern Virginia confronting it on the opposite bank of the same river, was strongly intrenched and commanded by the acknowledged ablest general in the Confederate army.

The country back to the James River is cut up with many streams, generally narrow, deep, and difficult to cross except where bridged.

The region is heavily timbered, and the roads narrow, and very bad after the least rain.

Such an enemy was not, of course, unprepared with adequate fortifications at convenient intervals all the way back to Richmond, so that when driven from one fortified position they would always have another farther to the rear to fall back into.
To provision an army, campaigning against so formidable a foe through such a country, from wagons alone seemed almost impossible.

System and discipline were both essential to its accomplishment.
The Union armies were now divided into nineteen departments, though four of them in the West had been concentrated into a single military division.