Agriculture during the 1800s in the Southern United States was significant because it was the beginnings of plantation farming. The plantations consisted of large fields of one type of crop, the first major crop was tobacco. A large amount of labour was required in farming the crops, so millions of African slaves were brought into the country. This was the start of the American slave trade. In 1831, the mechanical reaper was invented by Cyrus McCormick, and this allowed crop yields to dramatically increase.