For the Confederate soldiers, rations were much scarcer than for Union soldiers. At first they seemed varied and sufficient, but in actual fact this never was true. For most part their rations were corn bread and bad beef. They also had a few vegetables, when available, salt and coffee. But as time when on substitutes for coffee became the norm. In 1861 the general commissary recommended that rice and molasses be used as a substitute for meat. By 1863, mule meat was issued as standard ration. There are many reports of men existing for days on handfuls of parched corn or field peas".
Union soldiers faired much better.. The rations were not luxurious but were adequate. John Billings in his "Hardtack and Coffee"reported, on the list of rations there was salt pork, fresh beef. salt beef, ham or bacon, hard breads, soft bread, potatoes, onions, occasionally, flour, beans, split peas, rice, dried apples, dried peaches, desiccated vegetables, coffee, tea, sugar, molasses, vinegar, salt, and pepper."
Thus the Union Army was better served . Most of the time they would have got the sufficient calorie intake. The Confederates would have been hard put to consume enough for the calorie intake needed.
During the times of poor food supplies, for Confederates, many new dishes were created. One such was "cush" or "slosh" which was made by putting small pieces of beef in bacon grease, then pouring water and "stewing it".
Information from Introduction in "Civil War Recipes Receipts from the Pages of Godey's Lady's Book", edited by Lily May Spaulding and John Spaulding.