What was the south's primary economic activity in 1861 was

Agriculture. The south was the agriculture capital of the country at the time and while the north relied upon voluntary immigrant workers in their industrial plants, the south relied upon forced slave labor which eventually led to the civil war.

exports of cotton fell 95 percent and the South had to restructure itself to emphasize food production and munitions production. After losing control of its main rivers and ports, it had to depend on a weak railroad system that, with few repairs being made, no new equipment, and federal raids, crumbled away. The financial infrastructure collapsed during the war as inflation destroyed banks and forced a move toward a barter economy for civilians. The government seized needed supplies and livestock (paying with certificates that were to be paid off after the war, but never were).