How long did slaves generally have to wait to be freed? Were there any cases of very remote plantations or farms that were able to keep the slaves insulated from the news and thus keep them enslaved longer?
Was there any sort of agency that enforced the freeing of slaves in the South? Is there any documented evidence of violence against these people? And when slaves were freed, was there any kind of financial or housing assistance given to them to help them get a new life started?
From what I understand the treatment of slaves and African-Americans post civil war was largely due to the northern occupation during reconstruction. Freemen were presided over by union soldiers whose job was to maintain peace and order and ensure that the south abide by the federal mandates. As soon as Hayes ended reconstruction, and the union soldiers left, you have the implementation of Jim Crowe laws and discrimination once again.
Edit: the union soldiers were there to enforce it, while the freedmens bureau was appointed to handle the affairs recently freed slaves. Handling tasks such as finding lost family members and the like. From what I understand, they were rather successful too. As far as how long it took for some slaves to be set free I can't say, I imagine it was as soon as war was declared over or maybe when union soldiers arrived to enforce it.
Source: college class I just finished, I'm on mobile but I can find a source if necessary.
From what I've read, many slaves declared their freedom immediately following Sherman's march. As the army came through, many slaves left their plantations to follow the army, which became a problem as the crowd grew. The newly freed people had no ability to support themselves, no jobs, no place to live, no way to feed themselves, etc. In general, none of these people understood what it was like to be reposnsible for their own well-being and expected the army to take care of them. There were enough logistical issues feeding the troops on an extended march through enemy territory.