Which of the following groups argued that slavery was necessary for the economy

Abolitionists. Defenders of slavery argued that the sudden end to the slave economy would have had a profound and killing economic impact in the South where reliance on slave labor was the foundation of their economy. The cotton economy would collapse. The tobacco crop would dry in the fields. Rice would cease being profitable. There is actually a book about it.

Abolitionist and the south argued that it was necessary because they needed them more than the south did

Yes, reasons why is sectionalism compromise of 1850 and secession i hope this