This is getting off topic. However, what is your basis for claiming his father was freed slave and that he was adopted? There were slaves that looked white and were almost all white, but what does that have to do with Beauregard? If it were true, it was covered up, as it would have created problems for him as a US and CSA officer.His name was "Toutant-Beauregard":Toutant, name of his father,slave liberated,Beauregard name of a french business man who had adopted him.There was no black men or jews in the old french aristocracy because it was forbidden to marry with a woman who had no french and catholic origines.The tolerance for the protestants makes that they could marry-for the period of interdiction 1685-1787 in the foreign ambassades,and Orange,or in front of the notary,the protestant cult having "officially" disappeared.
What is the relevance that there were no blacks in the old French aristocracy? Beauregard was not part of the old French aristocracy, although he was partly descended from it.
There were "black" slave owners. Some were set up by their fathers and others were free blacks who acquired wealth. My understanding is this occurred more in French areas than elsewhere in the US south. After Reconstruction in the US south, there were strict rules that anyone with any black ancestry was black. However, many people of slave ancestry who appeared white "passed" as white.