I've failed you. I can't find the first black student at BYU. I did find some other facts that may interest you though (remember that the priesthood and temple ban was lifted in 1978):
- While BYU was never formally racially segregated, there certainly was opposition to welcoming black faculty and students. In 1954 Apostle Mark E. Peterson told a CES audience at BYU, "I think the Lord segregated the Negro and who is man to change that segregation?" In 1960 President Ernest L. Wilkinson stopped a subordinate from hiring a black professor, saying “I wish we could take him on our faculty, but the danger in doing so is that students and others take license from this, and assume that there is nothing improper about mingling with the other races. Since the Lord, himself, created the different races and urged in the Old Testament and other places that they be kept distinct and to themselves, we have to follow that admonition.”
- In 1965 Darius Gray became one of two African American students at BYU. (This is the first reference I can find to African American students being at BYU, though none of the sources indicated that Gray was the first.) That same year President Wilkinson wrote that Harold B. Lee was "protesting vigorously over our having given a scholarship at the B.Y.U. to a negro student from Africa. Brother Lee holds the traditional belief as revealed in the Old Testament that the races ought to be kept together and that there is danger in trying to integrate them on the B.Y.U. campus."
- In 1966 Gray started a relationship with a white girl. He was summoned to meet with his dean and was told that, if he continued that relationship, he would have to drop out. This may be due in part to Harold B. Lee telling President Wilkinson in 1960, "If a granddaughter of mine should ever go to BYU and become engaged to a colored boy there, I would hold you responsible." Gray transferred that year.
- In 1970 Wynetta Willis Martin became the first African American faculty member at BYU.
- In the 1980s, Keith N. Hamilton became the first African American graduate of BYU Law school.
- In 2002, Robert Foster became the first black student body president of BYU.
Judging by the quotes from 1954 and 1960, I'm guessing the first African American student enrolled around 1960-1965?
If you want to have a fun "Where's Waldo" moment, here's a picture I found from the 1950s. People are grouped geographically, which may help you see if there was an African American student at BYU at that time. I may be mistaken, but the student to the bottom right of the "Peru" sign might be black...?
Unfortunately there isn't a concrete date on this picture, so that doesn't help a ton.
If anyone knows the answer, please leave a correction!
-guppy of doom