Sorry if I was confusing.
Yes, slavery ended in 1862 with the Emancipation Proclamation. The Great Depression started in 1929, 67 years after slavery had ended.
The vast majority of cotton farms in the South did not own slaves during slavery. So while black slaves were used to pick cotton, there were many more whites picking cotton.
Cotton production didn't stop just because slavery ended. So by the time my dad came around he and my grandfather were picking cotton for a living. My dad hated it and left when he was about 18 and headed for the city to find a job.