Slave revolts were few and far between, but fairly bloody when they happened. Of course, like the medieval lords that they were, the Slavocrats' responses to revolts was always far bloodier.
As to the Civil War and the slaves that were kept down, well, for the most part, they weren't. If the Union Army got to within 100 miles of the slaves, they were gone. And CSA law insured exemptions from military service for slavers and their overseers, depending on their number of slaves. So to some degree, in the case of individual plantations, and the degree over which they controlled communications, the slaves just didn't know what was going on. A good example of this is the African-American holiday of "Juneteenth". Celebrated in Texas, because the Whites refused to even TELL their slaves that they were free until when on June 14th 1865, with the arrival of the Union Army in East Texas, it was left to the Yankees themselves to tell the EX-slaves that they had actually been free for two full months!
To a certain degree, the slavers, or in some cases, their spouses, had been forced to "come to an understanding" with their slaves if they didn't want to see mass runoffs. As in, no whips, no use of chattel, no selling of slaves. But anyone who had practiced mutilation could expect to see their slaves gone whatever the promises, and whatever the distances to the nearest Union soldier.
No problem with any of this - only with the idea some on this thread seem to have, ie that a victorious CSA would be brought down any time soon by a "massive slave revolt". I can't see the slightest reason for believing any such thing.