A quadroon is one-fourth African black and thus easily classed as black in the United States, yet three of this person's four grandparents are white. An octoroon has seven white great-grandparents out of eight and usually looks white or almost so.oss of security within the minority community, and fear and distrust of the white world are also factors. It should now be apparent that the definition of a black person as one with any trace at all of black African ancestry is inextricably woven into the history of the United States.
AD or A.D. stands for Anno Domini and is a label for numbering years after Christ was born. BC or B.C. means Before Christ. The year Christ was born is considered AD 1 and the year before that is labeled 1 BC. Historians use a nomenclature with less religious connotation: namely CE/BCE where CE means Common Era and BCE stands for Before Common Era.
Overview: CE usually stands for  Common Era .. AD is an abbreviation for  Anno Domini  in Latin or  the year of the Lord  in English. Both measure the number of years since the approximate birthday of Yeshua of Nazareth (a.k.a. Jesus Christ) a little over two millennia ago. CE and AD have the same value.