The statement that is true about cotton is that it was the primary export and the major source of southern wealth. Cotton was a hugely important crop in the antebellum South and was the backbone of the southern economy. The southern states produced over two-thirds of the world's cotton supply, and cotton exports accounted for a significant portion of the South's income. The production of cotton was not limited to the Upper South, and it was grown by both large and small farmers, including those who did not own slaves. By 1860, the United States did indeed produce almost half of the world's cotton supply, highlighting the importance of cotton to the global economy at the time.