This question is rather ambiguous as stated, so Revolutionary War was changed to Civil War.
Before the Civil War, because indentured labor was costly,slavery was practiced on the huge plantations of the South that grew such plants as tobacco, sugar cane, rice, and cotton which required picking during harvest time by numerous people. Interestingly, however, the total number of slave owners was 385,000, amounting to approximately 3.8% of the Southern and Border states population. So, fewer than one-third of Southern families actually owned slaves, indicating that it may be a misjudgment of all Southerners of the time to condemn them for slavery since many were little more than indentured laborers themselves.
In a profitable market, slaves were bought and sold like chattel, viewed as little more than animals and property, forced to work as many as fifteen hours a day. But, as they helped to contribute to the owners profits, few of the owners resembled Simon Legree as Harriet Beecher Stowe would have her readers believe (she later admitted her falsity was to incite Northerners). Instead, the wives of the plantation owners often tended the sick in the slave quarters in order to keep the workers healthy. In the mansions, house servants were much better off than the field workers, and women who were nursing their own babies were often wet nurses for the owners' babies. Nevertheless, even though slaves were not generally treated brutally, there were certainly many unconscionable incidents of severe cruelty for "misbehavior." Most of the time, as Twain portrays in Huck Finn who is surprised when Jim cries and speaks of his family, owners did not think of the slaves as real human beings with many of the same sensitivities as they. Their heartless selling of slaves' children and separation of husband and wife and sexual exploitations were, indeed, inexcusable.
Historical records attest to the fact that the Civil War was waged more for states' rights than it was for slavery per se verifying why many Southern families volunteered their sons to go to war since only one-third of the families own slaves. [Statistics show that every single Southern family lost a male member in the Civil War.] After the Civil War in which General Sherman razed Atlanta and burned much of the South in his infamous "March to the Sea," there was tremendous resentment among Southerners for former slaves, whom they perceived as partly responsible for this war. In addition, there was fear and hatred of the hundred of freed slaves, who had no homes or money and felt it necessary to steal in order to survive. This condition and others gave rise to the Klu Klux Klan that violently struck back at Negroes and at the Northern Jewish carpetbaggers, whom they felt had come to exploit people and make profits at the expense of the South. Southerners were also resentful of the conditions of the Emancipation Proclamation which did not affect Northern states:
On January 1, 1863 Lincoln signed the Emancipation Proclamation extending freedom to all slaves in the seceded states. In practice, only applied to slaves in states under confederate control, in other words, in precisely those places where Lincoln's words had no power.
--The American Antiquarian Society