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: Bleeding Kansas. Proposed by Sen. Stephen Douglas of Illinois, the Kansas-Nebraska Act essentially repealed the line imposed by the Missouri Compromise. Douglas, an ardent believer in grassroots democracy, felt that all the territories should be subject to popular sovereignty.
Causes of secession. The causes of the Civil War were complex and have been controversial since the war began. James C. Bradford wrote that the issue has been further complicated by historical revisionists, who have tried to offer a variety of reasons for the war. Slavery was the central source of escalating political tension in the 1850s.