I actually just finished reading Levine's The Fall of the House of Dixie less than an hour ago. He discusses three major responses from disaffected slaveowners.

Firstly, the majority of planters attempted to keep some form of more-or-less legal control over the freedmen, which eventually developed into the Ku Klux Klan, sharecropping, and segregation.

Secondly, some attempted to leave the country. Many went to Brazil, but they weren't able to take slaves with them - Brazil was a long sea voyage away, and after four years of war and blockade, planters wouldn't be able to charter and provision a fleet for themselves (to say nothing of how the international slave trade had been banned for decades.) Also, a party of several hundred under General Kirby Smith and Commodore Matthew Maury went to Mexico, to join the French puppet Emperor Maxamilian. They brought slaves, hoping to start new plantations. However, slavery had long been illegal in Mexico, and not even the Confederate-sympathizing Maxamilian had restored it, so (to quote ex-general Hindman) "all our negroes decided to leave us upon our arrival here." Maxamilian's defeat and execution in 1867 put a final end to this project.

Thirdly, there were some who tried to hide news of emancipation from their slaves. Levine mentions incidents in Texas and Georgia, including one master who explained it by saying Lincoln's death had restored slavery. One African Methodist Episcopal missionary in Georgia said, even four months after Appomattox, "The people do not really know that they are free." This did eventually fail, one plantation at a time, without much fanfare. Levine quotes one newly-freed girl saying "We stayed [on the plantation] another year after freedom" until "we finally found out we were free and left." Sadly, though Levine doesn't speculate, it's unlikely she was the last to learn.