A controversial issue at the 1787 Constitutional Convention was whether slaves were counted as part of the population in determining state representation in Congress or whether they were instead considered property and not considered as such for representation. Delegates from states with a large population of slaves argued that slaves should be regarded as persons in determining representation, but as property if the new government collected taxes on states on the basis of population. Delegates from states where slavery had become rare argued that slaves should be involved in taxation, but not in the provision of representation. Historian Garry Wills speculated that Jefferson would have lost the presidential elections of 1800 without the votes of additional slaves. Even “slavery would have been excluded from Missouri… India`s policy of estrangement from Jackson would have failed… Wilmot Proviso would have forbidden slavery in Denern won by Mexico… The Kansas-Nebraska bill would have failed.  While the three-fifths compromise could favour the Southern countries because of their large slave populations, Connecticut`s compromise tended to favour the (usually smaller) northern states. Support for the new Constitution was based on the balance of these sectoral interests.  The three-fifths compromise was a compromise reached in 1787 at the United States Constitutional Convention among the delegates of the federal states. Delegates argued over whether and how slaves would be counted in determining the total population of a state, as that number would determine the number of seats in the House of Representatives and the amount of taxes. The compromise had three out of five slaves as a people, which gave the southern states a third more seats in Congress and a third more votes than if slaves had been ignored, but less so than if slaves and free men had been counted in the same way.
The compromise was proposed by delegate James Wilson and seconded by Charles Pinckney. 143 members of Congress from other regions tried to reduce voting rights in the South because blacks were disenfranked, but a 1900 proposal never came to fruition. Ironically, this is because the South had too much representation in Congress to allow for change. Until the 1960s, the Southern Democrats, known as Dixiecrats, continued to have disproportionate power in Congress. This power was based in part on the black inhabitants, counted for representation, but prevented from voting by grandfather clauses and other laws that threatened their livelihoods and even their lives. The Teniecrates used the power they had in Congress to block attempts to make the South a fairer place. The three-fifths compromise, first introduced on June 11, 1787 by James Wilson and Roger Sherman, accounted for three-fifths of those enslaved. This agreement meant that the southern states received more votes than if the enslaved population had not been counted at all, but fewer votes than if the enslaved population had been fully counted.