Article one of the Constitution details the following while explaining how the Legislative branch of government was to work:
Representatives and direct Taxes shall be apportioned among the several States which may be included within this Union, according to their respective Numbers, which shall be determined by adding to the whole Number of free Persons, including those bound to Service for a Term of Years, and excluding Indians not taxed, three fifths of all other Persons.
Many argue that the founders were indeed racist, as they did not believe slaves were full human beings. It says right there, plain as day, that slaves should be counted as three fifths person... case closed, right?
Well, hang on there a minute... there may be more to the story. While many of the founders from the South were slave owners, they also recognized the inhumanity of the practice and knew that it's days were numbers. In fact Thomas Jefferson, the principle author of the Declaration of Independence, wrote this famous phrase into the Declaration:
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.
So how could a man who owned slaves himself, pen such a contradictory assertion? Let's look at how Montecello.org describes Thomas Jefferson's views on slavery:
Throughout his entire life, Thomas Jefferson was a consistent opponent of slavery. Calling it a “moral depravity” and a “hideous blot,” he believed that slavery presented the greatest threat to the survival of the new American nation. Jefferson also thought that slavery was contrary to the laws of nature, which decreed that everyone had a right to personal liberty. These views were radical in a world where unfree labor was the norm.
Many of the founders, like Thomas Jefferson, were conflicted. They knew slavery was a stain on the new nation's history, but they also knew that Americans living in the southern states had not evolved to the same realization. If America were to stay together as a fledgling nation, the political reality of changing minds on the topic of slavery would take years if not decades.
James Madison, the principle author of the Constitution and a slave owner himself, wrote the three fifths clause. Was James Madison racists? Hardly. This from the James Madison Museum:
James Madison's feelings about the slavery issue become even clearer as events led to the Federal Convention of 1787. In his treatise written before the convention, "Vices of the Political System of the United States," Madison wrote, "Where slavery exists the republican Theory becomes still more fallacious. At the convention Madison worked hard to keep direct reference to the word "slave" out of the Constitution. On June 30th, in the heat of the debate over representation in the Congress, James Madison offered what he thought was a compromise solution. Seeing that the true division was not the big states against the little ones but the North against the South, he proposed that the representation in one house be based on the number of free inhabitants in each state plus three-fifths of the number of slaves. The second house would be based solely on the number of free inhabitants. He also worked to free the nation of the slave trade problem.
So contrary to popular belief, counting slaves as three fifths persons in the constitution had nothing to do with how the founders viewed slaves. James Madison fought for that compromise as longer term political tactic to reduce the voting influence of the southern slave owning states in the new government.
While the founders hoped for a gradual peaceful political solution to end slavery, as we all know, it would take another 70 years, and ultimately a bloody civil war, to finally dismantle the horrific institution of slavery.