Depends...

Many of them were financially devastated as much of their long term wealth was defined by the worth of the actual slave.

Many slaves did flee the plantation system and moved North and West if they were able to, some fled to the cities to find work. For the large part, a significant number remained to become either paid farm labor or became sharecroppers.

Sharecropping is conceptially similar to the classical understanding of "Feudalism", but with significant differences. The former slaves, now called freedmen, would work a section of the plantation property in order to pay rent on a place to live and some living expenses. Mostly, they would sell or turn over a significant portion of their crop to the plantation owner to pay their rent and bills.

The ideal scenario of this, which was more the exception to the rule, is Dockery Plantation, or Dockery Farms. While this place was established in 1895, it does represent the structure that many of these plantations which survived took on. The plantations developed their own stores, the blacksmiths and other service providers became private businesses, all of whom paid rent to the owners, who often were the former slave owners.

However, this was not always the case. Many plantations were simply abandoned as the owners were now destitute. They either sold what property they could and moved into the cities, out West, or even out of the Country. Many were purchased by "carpetbaggers" and others who had gained wealth recently or by smart financial decisions. Many plantations were broken up parcel by parcel with the families maintaining a smaller farmstead around the main house. In a few cases, these homes were leased out to others, or even turned into apartments if they were located in an urban area such as Natchez.

Many owners changed their line of business entirely. They expanded into manufacturing textiles (one of the few boom industries in the post-war South), became merchants, professional tradesmen (lawyers, doctors, etc.). Through these different measures, many of them maintained a standard of living higher than the average anSoutherner, but never close to what was had before the war. To this day, may Southern families of note can trace their lineage to these old plantation owners.

This is a good source to work with.