No, they did not. The northern leaders in DC tried to tax them heavily, but did NOT control them.
Not just tax them, but also force them to pay the Northern industries to handle all their goods, from shipping, to banking, to insurance, to warehousing, and all handling of the money.
The North was getting 60% of all the revenue produced by slavery in the South. They were making more money from slavery than the plantations were!
And controlling a man's money is the biggest part of controlling a man.