riddle - separate with a riddle, as grain from chaff screen sift, sieve, strain - separate by passing through a sieve or other straining device to separate out coarser elements; sift the flour
Causing the Civil War. Historically, textbooks have taught that incompatibility between northern and southern economies caused the Civil War. The industrial revolution in the North, during the first few decades of the 19th century, brought about a machine age economy that relied on wage laborers, not slaves.
Causes of the Civil War. Causes for the outbreak of Civil War existed in plenty and one of the most prominent among them was the prevalence of slavery in the United States during this period. While the economy of the Northern states was driven by industries, the same was driven by agriculture in the Southern states.