This argument is not supposed to outline United States today, it is to argue on the original intent of the founding fathers, and that they were indeed as we say today- "Racist".
The first immigration act limited immigration to quote "free white men"
Laws existed so White Americans will not miscegenation.
".... It will probably be asked, Why not retain and incorporate the blacks into the state, and thus save the expense of supplying, by importation of white settlers, the vacancies they will leave? Deep rooted prejudices entertained by the whites; ten thousand recollections, by the blacks, of the injuries they have sustained; new provocations; the real distinctions which nature has made; and many other circumstances, will divide us into parties, and produce convulsions, which will probably never end but in the extermination of the one or the other race..."
James Madison on Equality
"To be consistent with existing and probably unalterable prejudices in the U. S. the freed blacks ought to be permanently removed beyond the region occupied by or allotted to a White population. The objections to a thorough incorporation of the two people are, with most of the Whites insuperable; and are admitted by all of them to be very powerful. If the blacks, strongly marked as they are by Physical & lasting peculiarities, be retained amid the Whites, under the degrading privation of equal rights political or social, they must be always dissatisfied with their condition as a change only from one to another species of oppression; always secretly confederated agst. the ruling & privileged class; and always uncontroulled by some of the most cogent motives to moral and respectable conduct. The character of the free blacks, even where their legal condition is least affected by their colour, seems to put these truths beyond question. It is material also that the removal of the blacks be to a distance precluding the jealousies & hostilities to be apprehended from a neighboring people stimulated by the contempt known to be entertained for their peculiar features; to say nothing of their vindictive recollections, or the predatory propensities which their State of Society might foster..."
"Which leads me to add one Remark: That the Number of purely white People in the World is proportionably very small. All Africa is black or tawny. Asia chiefly tawny. America (exclusive of the new Comers) wholly so. And in Europe, the Spaniards, Italians, French, Russians and Swedes, are generally of what we call a swarthy Complexion; as are the Germans also, the Saxons only excepted, who with the English, make the principal Body of White People on the Face of the Earth. I could wish their Numbers were increased."
In answer, I say, that, at the time I drew that constitution, I perfectly knew that there did not then exist such a thing in the Union as a black or colored citizen, nor could I then have conceived it possible such a thing could have ever existed in it; nor, notwithstanding all that has been said on the subject, do I now believe one does exist in it."
To conclude, this is not written in support of the policies of our founding fathers, but an acknowledgement of their beliefs and what they wanted the future of this nation to be