Which is exactly why the Northern powers wanted them to keep working to stream money into their pockets. The South leaving takes that labor force out of the control of the Northern power brokers.
The South did 500 million in trade with the North, and 200 million in trade with Europe.
That was almost all slave produced money.
The corrupt evil Northerners who enriched themselves off of slave money wanted to keep that gravy train going.
Numbers I've seen say 1860 cotton exports totaled ~$200 million and Southern "imports" from the North also totaled ~$200 million.
Those are important numbers, but the US Gross Domestic Product (GDP) in 1860 came in around $4.4 billion, of which the South totaled around 15%, or >$700 million.
In 1861 the loss of Southern exports, imports & GDP did disrupt the Northern economy, temporarily, by about 15%.
But the Union economy & GDP soon adjusted and by war's end had more than doubled.
The Southern economy was noteworthy for its dependence on cotton exports, and its lack of manufacturing capacities.