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: The Collapse of the Two-Party System. The tensions between North and South were mirrored in a growing schism in the nation's political parties. Following the compromise of 1850 and the crisis in Kansas, the nation's two major parties, the Whigs and Democrats, began to fracture along regional lines.