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
Causes of the Civil War: Abolitionism. The issue of slavery was further heightened by the rise of the Abolitionist movement in the 1820s and 1830s. Beginning in the North, adherents believed that slavery was morally wrong rather than simply a social evil.
History & Culture. The US Civil War lasted from 1861 to 1865 and led to over 618,000 casualties. Its causes can be traced back to tensions that formed early in the nation's history. Economic and social differences between the North and the South. With Eli Whitney's invention of the cotton gin in 1793, cotton became very profitable.