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.
The only cause of the war was that the South was invaded and responded to Northern aggression. I respectfully disagree with those who claim that the War Between the States was fought over slavery or that the abolition of slavery in the Revolutionary Era or early Federal period would have prevented war.