Answer:
C. Cotton made up 60 percent of all US exports in 1860.
Step-by-step explanation:
Cotton was one of the core ingredients or important item of the world's important industries in the early times. The industry has grown large across the globe by the manufacturing and production of cloths and cotton yarns.
USA was one of the leading exporters of cotton to the European countries in the early 1980s. The soil of USA was rich in cotton cultivation and also due to large number of slaves who worked in the cotton farms made USA to produce more and export more cotton.
On the eve of American Civil War, by the year 1860, cotton was accounted for nearly 60% of American exports. It represents a total value of about $200 million in a year.