The price of field slaves in the United States quadrupled during the first half of the nineteenth century, largely because of the expansion of what plantation crop?
A. lobacco
B. soybeans
C. wheat
D. collon

Historians have recently discovered a historical journal published in the early twentieth century. the journal contains facts based on original sources about the downfall of the early byzantium empire. historians consider this long-lost journal to be a breakthrough in their understanding of the byzantium empire. based on this information, the journal is a source.