Before the Civil War in 1861, USA depended mostly on tariffs and customs duties for its revenue. However, immediately before the war, the Treasury funds were very low. After the war began, both the North and the South had to find many different methods to fund the costs of the war and maintain revenues.
The South resorted to borrowing and printing money, as well as selling bonds. While the North also borrowed money and sold bonds--and that had a better outcome in the North because wealthy families were encouraged to buy bonds and support the war--it relied more on imposing higher taxes on products and services. Combined with income taxes, this boosted the revenue by about 21%. So the correct answer is B.
