How close did the American Congress or Presidency come to peacefully abolishing slavery before the Civil War?

by EconomistMagazine

With controversy about the Confederate battle flag raging in the media and the public eye this seemed like a good time to ask this question. The issue of slaves in America was solved by the Civil War as it was impossible to legislate this problem out of existence. I'm certain many attempts were made to right this wrong however, so please educate me, how close did people actually come to freeing the slaves before Lincoln?

Irishfafnir

They never came remotely close, freeing the slaves would have required constitutional change and a truly massive compensation plan for the slave owners. Now a number of states did debate freeing their slaves and Virginia came within a few votes in the 1830's, and Delaware seemed to be close to freeing their slaves multiple times throughout the 19th century, Maryland also flirted with the idea in the 1830's.