Why was slavery allowed in the south for so long?

Slavery was a thorny problem when the Constitution was written in 1787. One of the main reasons it was allowed to exist at that time was the belief that it was adying institution and would eventuallywither away. This was indeed the belief of both George Washington and Thomas Jefferson, both substantial slave holders in Virginia. What gave new economic life to slavery was the invention of the cotton gin by Eli Whitney in the very early 1800's. The rise of cotton cultivation, the most lucrative crop of the time, spanning the areas from North Carolina to Texas, spurred the use of African slavery to levels that the Founding Fathers could never have imagined. By 1860 the very economic foundation of every state of the future Confederacy save two, Virginia and Tennessee, was based on cotton monoculture. It is one of the supreme ironies of the American Civil War that most of the bloodshed occurred in the twoConfederate states least affected by slavery and King Cotton.