DiogenesLamp: "That's because they had never planned to free them in the first place.
That became a war tactic in 1863, and it was meant to damage Southern efforts to get recognition from other countries as well as provoke slave desertions and insurrections."
No, not 1863 -- "contraband of war" first became an issue early in war, spring of 1861.
During the war emancipation became an ever bigger issue which the Union responded to, in part, by hiring or enlisting hundreds of thousands of escaped slaves.
Hundreds of thousands more escaped slaves were sheltered in over 100 "Contraband camps".
Tejas Rob: "Thousands of people without a pot to piss in or a window to throw it out were left to their own accord, which caused chaos for decade upon decade, and we are still paying for that today."
Certainly not "for decade upon decade" because all of the chaos, such as it may have been, ended abruptly in 1876, when Union troops were forced to withdraw from former Confederate states and Southern whites reestablished political & social control, effectively nullifying the 13th, 14th & 15th Amendments for the next nearly 100 years.
Compared to 1860 US cotton production rose 20% by 1870, 30% by 1880, 50% by 1890 and today is roughly five times greater.
So the Southern economy did not permanently collapse.
DiogenesLamp: "I have read that huge numbers died of starvation, exposure and disease in the after math of the war. Others tell me these claims are made up, but it seems reasonable to me to believe that people tossed out of their existing lives might very well have had a hard time of it."
For certain, everyone had "a hard time of it", but there is no record of large numbers dying from starvation or abuse.
The simple reason is that while many did leave to find their relatives & friends sold away, most simply stayed where they were and continued life as it had been until different arrangements were made -- i.e., share cropping.