How The Civil War Soldiers Marched

In the army of the Potomac there were two species of marching employed,--in "heavy marching-order," and in "light marching-order." The former meant that the troops were to carry all they possessed with them; the other was to march with only the musket, ammunition, haversack, and canteen, thus being in trim for working or fighting. Every order to march specified one or the other manner. For heavy marches, two or three hours~ notice were usually given, so that time might be had for preparation; light marches, unless to picket, were generally to be commenced on the instant. Another style of order, always implying light marching-order, was sometimes made. This was "to be held in readiness to march at five minutes notice." Such an order as this was given when an engagement was in progress or anticipated, and the soldiers stood in line behind their musket-stacks until the order was rescinded or they were marched off in accordance with it.
In a heavy march to a new camp, the generals of division and brigade would first arrange the order of the brigades and artillery on the line of march, and next the order of the regiments of each brigade. This would all be specified in the official order commanding the march, and every part of the whole would be able to, and usually did, fall into its proper place in the line, without confusion.
The division general and staff preceded the division, and each brigadier and staff rode at the head of his brigade. Artillery rolled along in regular order--cannon, caisson, forge and ammunition wagon--to the end of their line. A regiment marched in the following manner: first the adjutant; then the pioneers; then the band and drum-corps; then the colonel and lieutenant-colonel; then the regiment, each man with his knapsack, haversack, canteen, and arms; and, bringing up the rear, the major, chaplain, and two surgeons, and, on foot, the hospital-knapsack-carrier. The colonel and adjutant sometimes exchanged places, however.
When these marches commenced, the men would be in regular military order, four abreast; but the first half-mile usually broke up all regularity.
The men before they had walked that distance would become dispersed all over the road, some walking along the banks and others in the ditches: a squad straggling along the centre would be all the orderly part of the regiment. Some ran down into gullies to search for water, and others started off to see curiosities. Many on long marches became exhausted by fatigue, and lay down under the trees to rest. In warm weather these marches--if prolonged to six or eight miles--were most trying. The suffering for water was usually the greatest trouble,--men carrying such heavy burdens as the soldiers requiring a great deal, and good water in any quantity being rarely discovered. Several halts of an hour or half-hour each were made in these marches, to allow the men to unsung knapsacks and rest or search for water, and to give the stragglers time to come up. The wagon-trains of each regiment followed at the rear of the division in the same order as the regiments marched. Each regimental quartermaster and quartermaster-sergeant attended the teams of his regiment.

A march to battle would be made in light marching-order, the men four abreast, and generally on the double quick. The men were held under strict discipline during such marches. The march from the field, however, was far different. If a victory had been gained, the men would cheer and talk, and the officers imposed no restraint. If a defeat had been suffered, angry arguments about its cause would foreshadow the disaster long before they reached the camp. A march to picket was in light marching order, and at common or quick time, and, when the picket tour was approached, it was conducted with great care and quietness. Homeward it was the same.
A march to chop wood or build roads and bridges would also be in light marching-order, at common or quick time, and--if the place to which the troops were going was not a dangerous one--without arms. Upon reaching the scene of labor, the command was usually given to an officer of engineers, who, through their company officers, directed the movements of the men. The march back to camp was as the one from it.

The general conduct of the troops upon these marches was such as could scarcely be found fault with. The burdens carried in heavy marches, and the discipline exercised in light ones, usually kept them to the road,--though, of course, in the former some would stray and visit the deserted houses in the fields. The inmates of every Negro-hut were besought for "hoecakes;" and when the amazed woman would naturally say, "Why, bress de Lord! how can I gub one cake to all o you?--dar, ye see dat I hab but one!"--some oily customers reply would come, "Give it to me, aunty; I asked you first." Plaguing the Negroes for "hoecakes" was usually the greatest extent of lawlessness when the troops were marching. No rapine or wanton destruction disgraced the marches of the army of the Potomac.

Source: "The Blue and The Gray" by Henry Steele Commanger, Article From Joel Cook's "The Siege of Richmond."