Your answer would be radical
Quite a vague title. Which war?
Enslaved workers supported the Southern economy because they harvested crops on the southern plantations, and this helped the South's agriculture-based economy.
The correct answer is the Underground Road!
The Underground Road was a network of safe houses and secret routes in 19th century that the slaves could use to escape to the north or to Canada. People helping the slaves were both black and white and both free and slaves were helping too!