What certain clause in the Declaration upset the south?

Jefferson's passage on slavery was the most important section removed from the final document.

Jefferson’s passage on slavery was the most important section removed from the final document. It was replaced with a more ambiguous passage about King George’s incitement of “domestic insurrections among us.” Decades later Jefferson blamed the removal of the passage on delegates from South Carolina and Georgia and Northern delegates who represented merchants who were at the time actively involved in the Trans-Atlantic slave trade. Jefferson’s original passage on slavery appears below.

Contributing factors  leading  to the harlem renaissance were the great migration of african americans to northern cities, which concentratedambitious  people in places where they could encourage each  other, and the first world war, which had created new industrial work opportunities for tens of thousands of people.