The South's economy was largely based on agriculture, particularly the cultivation of cotton. Cotton was a cash crop that could be sold for a profit on the global market, but it required a great deal of labor to produce. The South relied on the North to provide this labor, in the form of slaves.
Manufactured Goods
The South also relied on the North for manufactured goods. The North had a more industrialized economy, and it produced a wide range of goods that the South needed, including clothing, tools, and machinery. The South did not have the same level of industrial development, so it was unable to produce these goods for itself.
Transportation
The South also relied on the North for transportation. The North had a more developed transportation infrastructure, including roads, canals, and railroads. The South did not have the same level of infrastructure, so it was more difficult for southerners to transport their goods to market.
Finance
The South also relied on the North for finance. The North had a more developed financial system, including banks and insurance companies. The South did not have the same level of financial development, so it was more difficult for southerners to obtain loans and insurance.
Overall
The South was dependent on the North for a number of reasons, including agriculture, manufactured goods, transportation, and finance. This dependency made the South vulnerable to the North, and it was a factor in the outbreak of the Civil War.